From db7b0f0024f1031c26c25d3d1d266832ae640e42 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 02:16:00 +0100
Subject: [PATCH 01/23] ls exercises

---
 individual-shell-tools/ls/script-01.sh | 2 ++
 individual-shell-tools/ls/script-02.sh | 2 ++
 individual-shell-tools/ls/script-03.sh | 2 ++
 individual-shell-tools/ls/script-04.sh | 4 ++++
 4 files changed, 10 insertions(+)

diff --git a/individual-shell-tools/ls/script-01.sh b/individual-shell-tools/ls/script-01.sh
index 241b62f5e..8f93bb79e 100755
--- a/individual-shell-tools/ls/script-01.sh
+++ b/individual-shell-tools/ls/script-01.sh
@@ -13,3 +13,5 @@ fi
 
 # TODO: Write a command to list the files and folders in this directory.
 # The output should be a list of names including child-directory, script-01.sh, script-02.sh, and more.
+
+ls
\ No newline at end of file
diff --git a/individual-shell-tools/ls/script-02.sh b/individual-shell-tools/ls/script-02.sh
index d0a5a10f4..b026cfd6c 100755
--- a/individual-shell-tools/ls/script-02.sh
+++ b/individual-shell-tools/ls/script-02.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command which lists all of the files in the directory named child-directory.
 # The output should be a list of names: helper-1.txt, helper-2.txt, helper-3.txt.
+
+ls child-directory
diff --git a/individual-shell-tools/ls/script-03.sh b/individual-shell-tools/ls/script-03.sh
index 781216d21..b259fcb1d 100755
--- a/individual-shell-tools/ls/script-03.sh
+++ b/individual-shell-tools/ls/script-03.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # TODO: Write a command which _recursively_ lists all of the files and folders in this directory _and_ all of the files inside those folders.
 # The output should be a list of names including: child-directory, script-01.sh, helper-1.txt (and more).
 # The formatting of the output doesn't matter.
+
+ls -R
\ No newline at end of file
diff --git a/individual-shell-tools/ls/script-04.sh b/individual-shell-tools/ls/script-04.sh
index 72f3817b3..061b4f3d0 100755
--- a/individual-shell-tools/ls/script-04.sh
+++ b/individual-shell-tools/ls/script-04.sh
@@ -16,8 +16,12 @@ echo "First exercise (sorted newest to oldest):"
 # TODO: Write a command which lists the files in the child-directory directory, one per line, sorted so that the most recently modified file is first.
 # The output should be a list of names in this order, one per line: helper-3.txt, helper-1.txt, helper-2.txt.
 
+ls -1t child-directory
+
 
 echo "Second exercise (sorted oldest to newest):"
 
 # TODO: Write a command which does the same as above, but sorted in the opposite order (oldest first).
 # The output should be a list of names in this order, one per line: helper-2.txt, helper-1.txt, helper-3.txt.
+
+ls -1tr child-directory
\ No newline at end of file

From 721d271cef0dcb94eeb52a5cf23605e3c2eea8b8 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 02:29:00 +0100
Subject: [PATCH 02/23] cat exercise

---
 individual-shell-tools/cat/script-01.sh         | 2 ++
 individual-shell-tools/cat/script-02.sh         | 2 ++
 individual-shell-tools/cat/script-03.sh         | 2 ++
 individual-shell-tools/cat/script-04-stretch.sh | 2 ++
 4 files changed, 8 insertions(+)

diff --git a/individual-shell-tools/cat/script-01.sh b/individual-shell-tools/cat/script-01.sh
index c85053e0f..da5ec5029 100755
--- a/individual-shell-tools/cat/script-01.sh
+++ b/individual-shell-tools/cat/script-01.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the contents of the helper-1.txt file inside the helper-files directory to the terminal.
 # The output of this command should be "Once upon a time...".
+
+cat ../helper-files/helper-1.txt
\ No newline at end of file
diff --git a/individual-shell-tools/cat/script-02.sh b/individual-shell-tools/cat/script-02.sh
index 01bbd5eab..f645a1aff 100755
--- a/individual-shell-tools/cat/script-02.sh
+++ b/individual-shell-tools/cat/script-02.sh
@@ -11,3 +11,5 @@ set -euo pipefail
 # It looked delicious.
 # I was tempted to take a bite of it.
 # But this seemed like a bad idea...
+
+cat ../helper-files/*.txt
\ No newline at end of file
diff --git a/individual-shell-tools/cat/script-03.sh b/individual-shell-tools/cat/script-03.sh
index 37573b0c1..e4e7c7fe3 100755
--- a/individual-shell-tools/cat/script-03.sh
+++ b/individual-shell-tools/cat/script-03.sh
@@ -9,3 +9,5 @@ set -euo pipefail
 # 1 It looked delicious.
 # 2 I was tempted to take a bite of it.
 # 3 But this seemed like a bad idea...
+
+cat -n ../helper-files/helper-3.txt
\ No newline at end of file
diff --git a/individual-shell-tools/cat/script-04-stretch.sh b/individual-shell-tools/cat/script-04-stretch.sh
index 00fe3c48b..9ba3dfeb2 100755
--- a/individual-shell-tools/cat/script-04-stretch.sh
+++ b/individual-shell-tools/cat/script-04-stretch.sh
@@ -13,3 +13,5 @@ set -euo pipefail
 # 3 It looked delicious.
 # 4 I was tempted to take a bite of it.
 # 5 But this seemed like a bad idea...
+
+cat ../helper-files/*.txt | cat -n
\ No newline at end of file

From e4bcf76693cee50d9858a66cf210e5830dcee92a Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 02:32:49 +0100
Subject: [PATCH 03/23] wc exercise

---
 individual-shell-tools/wc/script-01.sh | 2 ++
 individual-shell-tools/wc/script-02.sh | 2 ++
 individual-shell-tools/wc/script-03.sh | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/individual-shell-tools/wc/script-01.sh b/individual-shell-tools/wc/script-01.sh
index c9dd6e5df..554bc7208 100755
--- a/individual-shell-tools/wc/script-01.sh
+++ b/individual-shell-tools/wc/script-01.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the number of words in the file helper-files/helper-3.txt.
 # The output should include the number 19. The output should not include the number 92.
+
+wc %  wc -w ../helper-files/helper-3.txt
\ No newline at end of file
diff --git a/individual-shell-tools/wc/script-02.sh b/individual-shell-tools/wc/script-02.sh
index 8feeb1a62..ae2ae870b 100755
--- a/individual-shell-tools/wc/script-02.sh
+++ b/individual-shell-tools/wc/script-02.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the number of lines in the file helper-files/helper-3.txt.
 # The output should include the number 3. The output should not include the number 19.
+
+wc -l ../helper-files/helper-3.txt
diff --git a/individual-shell-tools/wc/script-03.sh b/individual-shell-tools/wc/script-03.sh
index 6b2e9d3d1..3bc287a1a 100755
--- a/individual-shell-tools/wc/script-03.sh
+++ b/individual-shell-tools/wc/script-03.sh
@@ -8,3 +8,5 @@ set -euo pipefail
 #        1       7      39 ../helper-files/helper-2.txt
 #        3      19      92 ../helper-files/helper-3.txt
 #        5      30     151 total
+
+wc ../helper-files/*.txt
\ No newline at end of file

From c48dcce2b8f101b64f94f767111e84b4744c5cec Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 02:47:11 +0100
Subject: [PATCH 04/23] grep exercise

---
 individual-shell-tools/grep/script-01.sh | 2 ++
 individual-shell-tools/grep/script-02.sh | 2 ++
 individual-shell-tools/grep/script-03.sh | 2 ++
 individual-shell-tools/grep/script-04.sh | 2 ++
 individual-shell-tools/grep/script-05.sh | 2 ++
 individual-shell-tools/grep/script-06.sh | 2 ++
 individual-shell-tools/grep/script-07.sh | 2 ++
 7 files changed, 14 insertions(+)

diff --git a/individual-shell-tools/grep/script-01.sh b/individual-shell-tools/grep/script-01.sh
index fb05f42f2..acf8b4a96 100755
--- a/individual-shell-tools/grep/script-01.sh
+++ b/individual-shell-tools/grep/script-01.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output every line in dialogue.txt said by the Doctor.
 # The output should contain 6 lines.
+
+grep ^Doctor: dialogue.txt
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-02.sh b/individual-shell-tools/grep/script-02.sh
index df6f85640..e05ea7ca6 100755
--- a/individual-shell-tools/grep/script-02.sh
+++ b/individual-shell-tools/grep/script-02.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output every line in dialogue.txt that contains the word Doctor (regardless of case).
 # The output should contain 9 lines.
+
+grep -i Doctor dialogue.txt
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-03.sh b/individual-shell-tools/grep/script-03.sh
index 5383fe578..a6fef46f2 100755
--- a/individual-shell-tools/grep/script-03.sh
+++ b/individual-shell-tools/grep/script-03.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the number of lines in dialogue.txt that contain the word Doctor (regardless of case).
 # The output should be exactly the number 9.
+
+grep -ic Doctor dialogue.txt
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-04.sh b/individual-shell-tools/grep/script-04.sh
index 80ee04776..24bb2dfd7 100755
--- a/individual-shell-tools/grep/script-04.sh
+++ b/individual-shell-tools/grep/script-04.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output every line in dialogue.txt that does not contain the word "Hello" (regardless of case).
 # The output should contain 10 lines.
+
+grep -iv Hello dialogue.txt
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-05.sh b/individual-shell-tools/grep/script-05.sh
index 1eb538185..2391a370e 100755
--- a/individual-shell-tools/grep/script-05.sh
+++ b/individual-shell-tools/grep/script-05.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output every line in dialogue.txt that contains the string "cure", as well as the line before that line.
 # The output should contain two pairs of two lines of text (with a separator between them).
+
+grep % grep -B 1 "cure" dialogue.txt
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-06.sh b/individual-shell-tools/grep/script-06.sh
index 5670e3b6c..c5b842195 100755
--- a/individual-shell-tools/grep/script-06.sh
+++ b/individual-shell-tools/grep/script-06.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the name of every `.txt` file in this directory which contains a line of dialogue said by the Doctor.
 # The output should contain two filenames.
+
+grep -l ^Doctor: *.txt 
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-07.sh b/individual-shell-tools/grep/script-07.sh
index 9670ebad9..2ebba084b 100755
--- a/individual-shell-tools/grep/script-07.sh
+++ b/individual-shell-tools/grep/script-07.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output, for each `.txt` file in this directory, how many lines of dialogue the Doctor has.
 # The output should show that dialogue.txt contains 6 lines, dialogue-2.txt contains 2, and dialogue-3.txt contains 0.
+
+grep -c ^Doctor: *.txt

From 8157633bd0a997a9cf5856403a744176879c926f Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 03:00:30 +0100
Subject: [PATCH 05/23] sed exercise

---
 individual-shell-tools/sed/script-01.sh | 2 ++
 individual-shell-tools/sed/script-02.sh | 2 ++
 individual-shell-tools/sed/script-03.sh | 2 ++
 individual-shell-tools/sed/script-04.sh | 2 ++
 individual-shell-tools/sed/script-05.sh | 2 ++
 individual-shell-tools/sed/script-06.sh | 2 ++
 6 files changed, 12 insertions(+)

diff --git a/individual-shell-tools/sed/script-01.sh b/individual-shell-tools/sed/script-01.sh
index d592970fc..5d35f024c 100755
--- a/individual-shell-tools/sed/script-01.sh
+++ b/individual-shell-tools/sed/script-01.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # TODO: Write a command to output input.txt with all occurrences of the letter `i` replaced with `I`.
 # The output should contain 11 lines.
 # The first line of the output should be: "ThIs Is a sample fIle for experImentIng wIth sed.".
+
+sed % sed 's/i/I/' input.txt
\ No newline at end of file
diff --git a/individual-shell-tools/sed/script-02.sh b/individual-shell-tools/sed/script-02.sh
index abdd64d06..0f32ffd6b 100755
--- a/individual-shell-tools/sed/script-02.sh
+++ b/individual-shell-tools/sed/script-02.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # TODO: Write a command to output input.txt with numbers removed.
 # The output should contain 11 lines.
 # Line 6 of the output should be " Alisha".
+
+sed 's/[0-9]*//g' input.txt
\ No newline at end of file
diff --git a/individual-shell-tools/sed/script-03.sh b/individual-shell-tools/sed/script-03.sh
index dd284a296..e70f4a600 100755
--- a/individual-shell-tools/sed/script-03.sh
+++ b/individual-shell-tools/sed/script-03.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output input.txt removing any line which contains a number.
 # The output should contain 6 lines.
+
+sed '/[0-9]/d' input.txt
diff --git a/individual-shell-tools/sed/script-04.sh b/individual-shell-tools/sed/script-04.sh
index 0052ac6c4..8ac6e7c5d 100755
--- a/individual-shell-tools/sed/script-04.sh
+++ b/individual-shell-tools/sed/script-04.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output input.txt replacing every occurrence of the string "We'll" with "We will".
 # The output should contain 11 lines.
+
+sed "s/We'll/We will/g" input.txt
diff --git a/individual-shell-tools/sed/script-05.sh b/individual-shell-tools/sed/script-05.sh
index 2dcc91a0c..990ac2f2c 100755
--- a/individual-shell-tools/sed/script-05.sh
+++ b/individual-shell-tools/sed/script-05.sh
@@ -6,3 +6,5 @@ set -euo pipefail
 # If a line starts with a number and a space, make the line instead end with a space and the number.
 # So line 6 which currently reads "37 Alisha" should instead read "Alisha 37".
 # The output should contain 11 lines.
+
+sed -E 's/^([0-9]+) (.*)$/\2 \1/' input.txt
diff --git a/individual-shell-tools/sed/script-06.sh b/individual-shell-tools/sed/script-06.sh
index 0b9390170..6dad6a948 100755
--- a/individual-shell-tools/sed/script-06.sh
+++ b/individual-shell-tools/sed/script-06.sh
@@ -8,3 +8,5 @@ set -euo pipefail
 # The output should contain 11 lines.
 # Line 3 should be "It contains many lines, and there are some things you may want to do with each of them.".
 # Line 11 should be "We also should remember, when we go shopping, to get 4 items: oranges, cheese, bread, olives.".
+
+sed 's/^\([0-9][0-9]*\) \(.*\)$/\2 \1/' input.txt
\ No newline at end of file

From 0d520d4953b13d2b271a1ae02ed1a4d580d57021 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 03:14:09 +0100
Subject: [PATCH 06/23] awk exercise

---
 individual-shell-tools/awk/script-01.sh | 2 ++
 individual-shell-tools/awk/script-02.sh | 2 ++
 individual-shell-tools/awk/script-03.sh | 2 ++
 individual-shell-tools/awk/script-04.sh | 2 ++
 individual-shell-tools/awk/script-05.sh | 2 ++
 5 files changed, 10 insertions(+)

diff --git a/individual-shell-tools/awk/script-01.sh b/individual-shell-tools/awk/script-01.sh
index 8db4390af..587ed2acb 100755
--- a/individual-shell-tools/awk/script-01.sh
+++ b/individual-shell-tools/awk/script-01.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output just the names of each player in `scores-table.txt`.
 # Your output should contain 6 lines, each with just one word on it.
+
+awk '{print $1}' scores-table.txt
\ No newline at end of file
diff --git a/individual-shell-tools/awk/script-02.sh b/individual-shell-tools/awk/script-02.sh
index 5956be9bd..a29bbbf1f 100755
--- a/individual-shell-tools/awk/script-02.sh
+++ b/individual-shell-tools/awk/script-02.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the names of each player, as well as their city.
 # Your output should contain 6 lines, each with two words on it, separated by a space.
+
+awk '{print $1, $2}' scores-table.txt
diff --git a/individual-shell-tools/awk/script-03.sh b/individual-shell-tools/awk/script-03.sh
index af7c6e8b9..67365bfa4 100755
--- a/individual-shell-tools/awk/script-03.sh
+++ b/individual-shell-tools/awk/script-03.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # TODO: Write a command to output just the names of each player along with the score from their first attempt.
 # Your output should contain 6 lines, each with one word and one number on it.
 # The first line should be "Ahmed 1".
+
+awk '{print $1, $3}' scores-table.txt
\ No newline at end of file
diff --git a/individual-shell-tools/awk/script-04.sh b/individual-shell-tools/awk/script-04.sh
index bf15703c7..6430de6dc 100755
--- a/individual-shell-tools/awk/script-04.sh
+++ b/individual-shell-tools/awk/script-04.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # TODO: Write a command to output just the names of each player in London along with the score from their last attempt.
 # Your output should contain 3 lines, each with one word and one number on it.
 # The first line should be "Ahmed 4".
+
+awk '$2 == "London" {print $1, $5}' scores-table.txt
\ No newline at end of file
diff --git a/individual-shell-tools/awk/script-05.sh b/individual-shell-tools/awk/script-05.sh
index d1680cb02..0df43b872 100755
--- a/individual-shell-tools/awk/script-05.sh
+++ b/individual-shell-tools/awk/script-05.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # TODO: Write a command to output just the names of each player along with the number of times they've played the game.
 # Your output should contain 6 lines, each with one word and one number on it.
 # The first line should be "Ahmed 3".
+
+awk '{print $1, NF-2}' scores-table.txt
\ No newline at end of file

From 98447832a531c63f945217869fed99915a532b9a Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 03:43:25 +0100
Subject: [PATCH 07/23] fix the errors

---
 individual-shell-tools/awk/script-04.sh  | 2 +-
 individual-shell-tools/grep/script-05.sh | 2 +-
 individual-shell-tools/sed/script-01.sh  | 2 +-
 individual-shell-tools/sed/script-06.sh  | 2 +-
 individual-shell-tools/wc/script-01.sh   | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/individual-shell-tools/awk/script-04.sh b/individual-shell-tools/awk/script-04.sh
index 6430de6dc..79da3d066 100755
--- a/individual-shell-tools/awk/script-04.sh
+++ b/individual-shell-tools/awk/script-04.sh
@@ -6,4 +6,4 @@ set -euo pipefail
 # Your output should contain 3 lines, each with one word and one number on it.
 # The first line should be "Ahmed 4".
 
-awk '$2 == "London" {print $1, $5}' scores-table.txt
\ No newline at end of file
+awk '$2 == "London" {print $1, $NF}' scores-table.txt
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-05.sh b/individual-shell-tools/grep/script-05.sh
index 2391a370e..497a6e7f0 100755
--- a/individual-shell-tools/grep/script-05.sh
+++ b/individual-shell-tools/grep/script-05.sh
@@ -5,4 +5,4 @@ set -euo pipefail
 # TODO: Write a command to output every line in dialogue.txt that contains the string "cure", as well as the line before that line.
 # The output should contain two pairs of two lines of text (with a separator between them).
 
-grep % grep -B 1 "cure" dialogue.txt
\ No newline at end of file
+grep -B 1 "cure" dialogue.txt
\ No newline at end of file
diff --git a/individual-shell-tools/sed/script-01.sh b/individual-shell-tools/sed/script-01.sh
index 5d35f024c..a0b748a63 100755
--- a/individual-shell-tools/sed/script-01.sh
+++ b/individual-shell-tools/sed/script-01.sh
@@ -6,4 +6,4 @@ set -euo pipefail
 # The output should contain 11 lines.
 # The first line of the output should be: "ThIs Is a sample fIle for experImentIng wIth sed.".
 
-sed % sed 's/i/I/' input.txt
\ No newline at end of file
+sed 's/i/I/' input.txt
\ No newline at end of file
diff --git a/individual-shell-tools/sed/script-06.sh b/individual-shell-tools/sed/script-06.sh
index 6dad6a948..ab15800eb 100755
--- a/individual-shell-tools/sed/script-06.sh
+++ b/individual-shell-tools/sed/script-06.sh
@@ -9,4 +9,4 @@ set -euo pipefail
 # Line 3 should be "It contains many lines, and there are some things you may want to do with each of them.".
 # Line 11 should be "We also should remember, when we go shopping, to get 4 items: oranges, cheese, bread, olives.".
 
-sed 's/^\([0-9][0-9]*\) \(.*\)$/\2 \1/' input.txt
\ No newline at end of file
+sed 's/, */, /g' input.txt
\ No newline at end of file
diff --git a/individual-shell-tools/wc/script-01.sh b/individual-shell-tools/wc/script-01.sh
index 554bc7208..22b7b8d9e 100755
--- a/individual-shell-tools/wc/script-01.sh
+++ b/individual-shell-tools/wc/script-01.sh
@@ -5,4 +5,4 @@ set -euo pipefail
 # TODO: Write a command to output the number of words in the file helper-files/helper-3.txt.
 # The output should include the number 19. The output should not include the number 92.
 
-wc %  wc -w ../helper-files/helper-3.txt
\ No newline at end of file
+wc -w ../helper-files/helper-3.txt
\ No newline at end of file

From f8a25cc75d40159333beae39705590984f6d0284 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 10:42:06 +0100
Subject: [PATCH 08/23] fix: correct sed script-01 solution

---
 individual-shell-tools/sed/script-01.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/individual-shell-tools/sed/script-01.sh b/individual-shell-tools/sed/script-01.sh
index a0b748a63..0bd78a317 100755
--- a/individual-shell-tools/sed/script-01.sh
+++ b/individual-shell-tools/sed/script-01.sh
@@ -6,4 +6,4 @@ set -euo pipefail
 # The output should contain 11 lines.
 # The first line of the output should be: "ThIs Is a sample fIle for experImentIng wIth sed.".
 
-sed 's/i/I/' input.txt
\ No newline at end of file
+sed 's/i/I/g' input.txt
\ No newline at end of file

From 19015e584cb2da2107dec365e50583cf750cf274 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 11:41:27 +0100
Subject: [PATCH 09/23] part1 number systems

---
 number-systems/Part-1.md | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/number-systems/Part-1.md b/number-systems/Part-1.md
index d8f9c290e..68b77ea0b 100644
--- a/number-systems/Part-1.md
+++ b/number-systems/Part-1.md
@@ -6,49 +6,49 @@ The goal of these exercises is for you to gain an intuition for binary numbers.
 
 The answers to these questions should be a number, either in binary, hex, or decimal.
 
-Q1: Convert the decimal number 14 to binary.
-Answer:
+Q1: Convert the decimal number 14 to binary. 0,2,4,8,16,32,64,128,256
+Answer: 1110
 
 Q2: Convert the binary number 101101 to decimal:
-Answer:
+Answer: 45
 
 Q3: Which is larger: 1000 or 0111?
-Answer:
+Answer: 1000
 
 Q4: Which is larger: 00100 or 01011?
-Answer:
+Answer: 01011
 
 Q5: What is 10101 + 01010?
-Answer:
+Answer: 11111
 
 Q6: What is 10001 + 10001?
-Answer:
+Answer: 100010
 
 Q7: What's the largest number you can store with 4 bits, if you want to be able to represent the number 0?
-Answer:
+Answer: 15
 
 Q8: How many bits would you need in order to store the numbers between 0 and 255 inclusive?
-Answer:
+Answer: 9
 
 Q9: How many bits would you need in order to store the numbers between 0 and 3 inclusive?
-Answer:
+Answer: 2
 
 Q10: How many bits would you need in order to store the numbers between 0 and 1000 inclusive?
-Answer:
+Answer: 10
 
 Q11: Convert the decimal number 14 to hex.
-Answer:
+Answer: E
  
 Q12: Convert the decimal number 386 to hex.
-Answer:
+Answer: 182
 
 Q13: Convert the hex number 386 to decimal.
-Answer:
+Answer: 902
 
 Q14: Convert the hex number B to decimal.
-Answer:
+Answer: 11
 
 Q15: If reading the byte 0x21 as a number, what decimal number would it mean?
-Answer:
+Answer: 33
 
 Q16: Continues in Part-2

From 3e44d1cb6d008aa8376492a43e019440110283c5 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 12:27:55 +0100
Subject: [PATCH 10/23] part 2 number system

---
 number-systems/Part-2.md | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/number-systems/Part-2.md b/number-systems/Part-2.md
index 68b0933d9..1fce42ee7 100644
--- a/number-systems/Part-2.md
+++ b/number-systems/Part-2.md
@@ -7,16 +7,18 @@ The goal of these exercises is for you to gain an intuition for binary numbers.
 The answers to these questions will require a bit of explanation, not just a simple answer.
 
 Q16: How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...)?
-Answer:
+Answer: If there is just one 1 in a binary number, then it is a power of 2. This is because each bit represents a power of 2, so if there is just one 1 bit in a binary number, the value represents a power of 2.
 
 Q17: If reading the byte 0x21 as an ASCII character, what character would it mean?
-Answer:
+Answer: !
 
 Q18: If reading the byte 0x21 as a greyscale colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
-Answer:
+Answer: It represents 33, which is in the range of 0–255 from dark to light. This value represents a very dark grey.
 
 Q19: If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be?
-Answer:
+Answer:  three one-byte => 
+AA | 00 | FF ==> AA : 10 * 16 + 10 * 1 = 170 | 00 : 0 * 16 + 0 * 1 = 0 | FF : 15 * 16 + 15 * 1 = 255
+so it reperesnt 170, 0, 255
 
 Q20: If reading the bytes 0xAA00FF as an RGB colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
-Answer:
+Answer: AA => 170 Red,  00 => 0 green , FF : 255 is blue

From ad6bc8ea9952e0efad0607ee8f1d2335c08d52e5 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 13:05:36 +0100
Subject: [PATCH 11/23] updated branch

---
 individual-shell-tools/awk/script-01.sh         | 2 --
 individual-shell-tools/awk/script-02.sh         | 2 --
 individual-shell-tools/awk/script-03.sh         | 2 --
 individual-shell-tools/awk/script-04.sh         | 2 --
 individual-shell-tools/awk/script-05.sh         | 2 --
 individual-shell-tools/cat/script-01.sh         | 2 --
 individual-shell-tools/cat/script-02.sh         | 2 --
 individual-shell-tools/cat/script-03.sh         | 2 --
 individual-shell-tools/cat/script-04-stretch.sh | 2 --
 individual-shell-tools/grep/script-01.sh        | 2 --
 individual-shell-tools/grep/script-02.sh        | 2 --
 individual-shell-tools/grep/script-03.sh        | 2 --
 individual-shell-tools/grep/script-04.sh        | 2 --
 individual-shell-tools/grep/script-05.sh        | 2 --
 individual-shell-tools/grep/script-06.sh        | 2 --
 individual-shell-tools/grep/script-07.sh        | 2 --
 individual-shell-tools/ls/script-01.sh          | 3 +--
 individual-shell-tools/ls/script-02.sh          | 2 --
 individual-shell-tools/ls/script-03.sh          | 2 --
 individual-shell-tools/ls/script-04.sh          | 4 ----
 individual-shell-tools/sed/script-01.sh         | 2 --
 individual-shell-tools/sed/script-02.sh         | 2 --
 individual-shell-tools/sed/script-03.sh         | 2 --
 individual-shell-tools/sed/script-04.sh         | 2 --
 individual-shell-tools/sed/script-05.sh         | 2 --
 individual-shell-tools/sed/script-06.sh         | 2 --
 individual-shell-tools/wc/script-01.sh          | 2 --
 individual-shell-tools/wc/script-02.sh          | 2 --
 individual-shell-tools/wc/script-03.sh          | 2 --
 29 files changed, 1 insertion(+), 60 deletions(-)

diff --git a/individual-shell-tools/awk/script-01.sh b/individual-shell-tools/awk/script-01.sh
index 587ed2acb..8db4390af 100755
--- a/individual-shell-tools/awk/script-01.sh
+++ b/individual-shell-tools/awk/script-01.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output just the names of each player in `scores-table.txt`.
 # Your output should contain 6 lines, each with just one word on it.
-
-awk '{print $1}' scores-table.txt
\ No newline at end of file
diff --git a/individual-shell-tools/awk/script-02.sh b/individual-shell-tools/awk/script-02.sh
index a29bbbf1f..5956be9bd 100755
--- a/individual-shell-tools/awk/script-02.sh
+++ b/individual-shell-tools/awk/script-02.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output the names of each player, as well as their city.
 # Your output should contain 6 lines, each with two words on it, separated by a space.
-
-awk '{print $1, $2}' scores-table.txt
diff --git a/individual-shell-tools/awk/script-03.sh b/individual-shell-tools/awk/script-03.sh
index 67365bfa4..af7c6e8b9 100755
--- a/individual-shell-tools/awk/script-03.sh
+++ b/individual-shell-tools/awk/script-03.sh
@@ -5,5 +5,3 @@ set -euo pipefail
 # TODO: Write a command to output just the names of each player along with the score from their first attempt.
 # Your output should contain 6 lines, each with one word and one number on it.
 # The first line should be "Ahmed 1".
-
-awk '{print $1, $3}' scores-table.txt
\ No newline at end of file
diff --git a/individual-shell-tools/awk/script-04.sh b/individual-shell-tools/awk/script-04.sh
index 79da3d066..bf15703c7 100755
--- a/individual-shell-tools/awk/script-04.sh
+++ b/individual-shell-tools/awk/script-04.sh
@@ -5,5 +5,3 @@ set -euo pipefail
 # TODO: Write a command to output just the names of each player in London along with the score from their last attempt.
 # Your output should contain 3 lines, each with one word and one number on it.
 # The first line should be "Ahmed 4".
-
-awk '$2 == "London" {print $1, $NF}' scores-table.txt
\ No newline at end of file
diff --git a/individual-shell-tools/awk/script-05.sh b/individual-shell-tools/awk/script-05.sh
index 0df43b872..d1680cb02 100755
--- a/individual-shell-tools/awk/script-05.sh
+++ b/individual-shell-tools/awk/script-05.sh
@@ -5,5 +5,3 @@ set -euo pipefail
 # TODO: Write a command to output just the names of each player along with the number of times they've played the game.
 # Your output should contain 6 lines, each with one word and one number on it.
 # The first line should be "Ahmed 3".
-
-awk '{print $1, NF-2}' scores-table.txt
\ No newline at end of file
diff --git a/individual-shell-tools/cat/script-01.sh b/individual-shell-tools/cat/script-01.sh
index da5ec5029..c85053e0f 100755
--- a/individual-shell-tools/cat/script-01.sh
+++ b/individual-shell-tools/cat/script-01.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output the contents of the helper-1.txt file inside the helper-files directory to the terminal.
 # The output of this command should be "Once upon a time...".
-
-cat ../helper-files/helper-1.txt
\ No newline at end of file
diff --git a/individual-shell-tools/cat/script-02.sh b/individual-shell-tools/cat/script-02.sh
index f645a1aff..01bbd5eab 100755
--- a/individual-shell-tools/cat/script-02.sh
+++ b/individual-shell-tools/cat/script-02.sh
@@ -11,5 +11,3 @@ set -euo pipefail
 # It looked delicious.
 # I was tempted to take a bite of it.
 # But this seemed like a bad idea...
-
-cat ../helper-files/*.txt
\ No newline at end of file
diff --git a/individual-shell-tools/cat/script-03.sh b/individual-shell-tools/cat/script-03.sh
index e4e7c7fe3..37573b0c1 100755
--- a/individual-shell-tools/cat/script-03.sh
+++ b/individual-shell-tools/cat/script-03.sh
@@ -9,5 +9,3 @@ set -euo pipefail
 # 1 It looked delicious.
 # 2 I was tempted to take a bite of it.
 # 3 But this seemed like a bad idea...
-
-cat -n ../helper-files/helper-3.txt
\ No newline at end of file
diff --git a/individual-shell-tools/cat/script-04-stretch.sh b/individual-shell-tools/cat/script-04-stretch.sh
index 9ba3dfeb2..00fe3c48b 100755
--- a/individual-shell-tools/cat/script-04-stretch.sh
+++ b/individual-shell-tools/cat/script-04-stretch.sh
@@ -13,5 +13,3 @@ set -euo pipefail
 # 3 It looked delicious.
 # 4 I was tempted to take a bite of it.
 # 5 But this seemed like a bad idea...
-
-cat ../helper-files/*.txt | cat -n
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-01.sh b/individual-shell-tools/grep/script-01.sh
index acf8b4a96..fb05f42f2 100755
--- a/individual-shell-tools/grep/script-01.sh
+++ b/individual-shell-tools/grep/script-01.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output every line in dialogue.txt said by the Doctor.
 # The output should contain 6 lines.
-
-grep ^Doctor: dialogue.txt
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-02.sh b/individual-shell-tools/grep/script-02.sh
index e05ea7ca6..df6f85640 100755
--- a/individual-shell-tools/grep/script-02.sh
+++ b/individual-shell-tools/grep/script-02.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output every line in dialogue.txt that contains the word Doctor (regardless of case).
 # The output should contain 9 lines.
-
-grep -i Doctor dialogue.txt
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-03.sh b/individual-shell-tools/grep/script-03.sh
index a6fef46f2..5383fe578 100755
--- a/individual-shell-tools/grep/script-03.sh
+++ b/individual-shell-tools/grep/script-03.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output the number of lines in dialogue.txt that contain the word Doctor (regardless of case).
 # The output should be exactly the number 9.
-
-grep -ic Doctor dialogue.txt
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-04.sh b/individual-shell-tools/grep/script-04.sh
index 24bb2dfd7..80ee04776 100755
--- a/individual-shell-tools/grep/script-04.sh
+++ b/individual-shell-tools/grep/script-04.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output every line in dialogue.txt that does not contain the word "Hello" (regardless of case).
 # The output should contain 10 lines.
-
-grep -iv Hello dialogue.txt
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-05.sh b/individual-shell-tools/grep/script-05.sh
index 497a6e7f0..1eb538185 100755
--- a/individual-shell-tools/grep/script-05.sh
+++ b/individual-shell-tools/grep/script-05.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output every line in dialogue.txt that contains the string "cure", as well as the line before that line.
 # The output should contain two pairs of two lines of text (with a separator between them).
-
-grep -B 1 "cure" dialogue.txt
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-06.sh b/individual-shell-tools/grep/script-06.sh
index c5b842195..5670e3b6c 100755
--- a/individual-shell-tools/grep/script-06.sh
+++ b/individual-shell-tools/grep/script-06.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output the name of every `.txt` file in this directory which contains a line of dialogue said by the Doctor.
 # The output should contain two filenames.
-
-grep -l ^Doctor: *.txt 
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-07.sh b/individual-shell-tools/grep/script-07.sh
index 2ebba084b..9670ebad9 100755
--- a/individual-shell-tools/grep/script-07.sh
+++ b/individual-shell-tools/grep/script-07.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output, for each `.txt` file in this directory, how many lines of dialogue the Doctor has.
 # The output should show that dialogue.txt contains 6 lines, dialogue-2.txt contains 2, and dialogue-3.txt contains 0.
-
-grep -c ^Doctor: *.txt
diff --git a/individual-shell-tools/ls/script-01.sh b/individual-shell-tools/ls/script-01.sh
index 8f93bb79e..754a44837 100755
--- a/individual-shell-tools/ls/script-01.sh
+++ b/individual-shell-tools/ls/script-01.sh
@@ -12,6 +12,5 @@ if [[ "${script_dir}" != "$(pwd)" ]]; then
 fi
 
 # TODO: Write a command to list the files and folders in this directory.
-# The output should be a list of names including child-directory, script-01.sh, script-02.sh, and more.
 
-ls
\ No newline at end of file
+# The output should be a list of names including child-directory, script-01.sh, script-02.sh, and more.
\ No newline at end of file
diff --git a/individual-shell-tools/ls/script-02.sh b/individual-shell-tools/ls/script-02.sh
index b026cfd6c..d0a5a10f4 100755
--- a/individual-shell-tools/ls/script-02.sh
+++ b/individual-shell-tools/ls/script-02.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command which lists all of the files in the directory named child-directory.
 # The output should be a list of names: helper-1.txt, helper-2.txt, helper-3.txt.
-
-ls child-directory
diff --git a/individual-shell-tools/ls/script-03.sh b/individual-shell-tools/ls/script-03.sh
index b259fcb1d..781216d21 100755
--- a/individual-shell-tools/ls/script-03.sh
+++ b/individual-shell-tools/ls/script-03.sh
@@ -5,5 +5,3 @@ set -euo pipefail
 # TODO: Write a command which _recursively_ lists all of the files and folders in this directory _and_ all of the files inside those folders.
 # The output should be a list of names including: child-directory, script-01.sh, helper-1.txt (and more).
 # The formatting of the output doesn't matter.
-
-ls -R
\ No newline at end of file
diff --git a/individual-shell-tools/ls/script-04.sh b/individual-shell-tools/ls/script-04.sh
index 061b4f3d0..72f3817b3 100755
--- a/individual-shell-tools/ls/script-04.sh
+++ b/individual-shell-tools/ls/script-04.sh
@@ -16,12 +16,8 @@ echo "First exercise (sorted newest to oldest):"
 # TODO: Write a command which lists the files in the child-directory directory, one per line, sorted so that the most recently modified file is first.
 # The output should be a list of names in this order, one per line: helper-3.txt, helper-1.txt, helper-2.txt.
 
-ls -1t child-directory
-
 
 echo "Second exercise (sorted oldest to newest):"
 
 # TODO: Write a command which does the same as above, but sorted in the opposite order (oldest first).
 # The output should be a list of names in this order, one per line: helper-2.txt, helper-1.txt, helper-3.txt.
-
-ls -1tr child-directory
\ No newline at end of file
diff --git a/individual-shell-tools/sed/script-01.sh b/individual-shell-tools/sed/script-01.sh
index 0bd78a317..d592970fc 100755
--- a/individual-shell-tools/sed/script-01.sh
+++ b/individual-shell-tools/sed/script-01.sh
@@ -5,5 +5,3 @@ set -euo pipefail
 # TODO: Write a command to output input.txt with all occurrences of the letter `i` replaced with `I`.
 # The output should contain 11 lines.
 # The first line of the output should be: "ThIs Is a sample fIle for experImentIng wIth sed.".
-
-sed 's/i/I/g' input.txt
\ No newline at end of file
diff --git a/individual-shell-tools/sed/script-02.sh b/individual-shell-tools/sed/script-02.sh
index 0f32ffd6b..abdd64d06 100755
--- a/individual-shell-tools/sed/script-02.sh
+++ b/individual-shell-tools/sed/script-02.sh
@@ -5,5 +5,3 @@ set -euo pipefail
 # TODO: Write a command to output input.txt with numbers removed.
 # The output should contain 11 lines.
 # Line 6 of the output should be " Alisha".
-
-sed 's/[0-9]*//g' input.txt
\ No newline at end of file
diff --git a/individual-shell-tools/sed/script-03.sh b/individual-shell-tools/sed/script-03.sh
index e70f4a600..dd284a296 100755
--- a/individual-shell-tools/sed/script-03.sh
+++ b/individual-shell-tools/sed/script-03.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output input.txt removing any line which contains a number.
 # The output should contain 6 lines.
-
-sed '/[0-9]/d' input.txt
diff --git a/individual-shell-tools/sed/script-04.sh b/individual-shell-tools/sed/script-04.sh
index 8ac6e7c5d..0052ac6c4 100755
--- a/individual-shell-tools/sed/script-04.sh
+++ b/individual-shell-tools/sed/script-04.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output input.txt replacing every occurrence of the string "We'll" with "We will".
 # The output should contain 11 lines.
-
-sed "s/We'll/We will/g" input.txt
diff --git a/individual-shell-tools/sed/script-05.sh b/individual-shell-tools/sed/script-05.sh
index 990ac2f2c..2dcc91a0c 100755
--- a/individual-shell-tools/sed/script-05.sh
+++ b/individual-shell-tools/sed/script-05.sh
@@ -6,5 +6,3 @@ set -euo pipefail
 # If a line starts with a number and a space, make the line instead end with a space and the number.
 # So line 6 which currently reads "37 Alisha" should instead read "Alisha 37".
 # The output should contain 11 lines.
-
-sed -E 's/^([0-9]+) (.*)$/\2 \1/' input.txt
diff --git a/individual-shell-tools/sed/script-06.sh b/individual-shell-tools/sed/script-06.sh
index ab15800eb..0b9390170 100755
--- a/individual-shell-tools/sed/script-06.sh
+++ b/individual-shell-tools/sed/script-06.sh
@@ -8,5 +8,3 @@ set -euo pipefail
 # The output should contain 11 lines.
 # Line 3 should be "It contains many lines, and there are some things you may want to do with each of them.".
 # Line 11 should be "We also should remember, when we go shopping, to get 4 items: oranges, cheese, bread, olives.".
-
-sed 's/, */, /g' input.txt
\ No newline at end of file
diff --git a/individual-shell-tools/wc/script-01.sh b/individual-shell-tools/wc/script-01.sh
index 22b7b8d9e..c9dd6e5df 100755
--- a/individual-shell-tools/wc/script-01.sh
+++ b/individual-shell-tools/wc/script-01.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output the number of words in the file helper-files/helper-3.txt.
 # The output should include the number 19. The output should not include the number 92.
-
-wc -w ../helper-files/helper-3.txt
\ No newline at end of file
diff --git a/individual-shell-tools/wc/script-02.sh b/individual-shell-tools/wc/script-02.sh
index ae2ae870b..8feeb1a62 100755
--- a/individual-shell-tools/wc/script-02.sh
+++ b/individual-shell-tools/wc/script-02.sh
@@ -4,5 +4,3 @@ set -euo pipefail
 
 # TODO: Write a command to output the number of lines in the file helper-files/helper-3.txt.
 # The output should include the number 3. The output should not include the number 19.
-
-wc -l ../helper-files/helper-3.txt
diff --git a/individual-shell-tools/wc/script-03.sh b/individual-shell-tools/wc/script-03.sh
index 3bc287a1a..6b2e9d3d1 100755
--- a/individual-shell-tools/wc/script-03.sh
+++ b/individual-shell-tools/wc/script-03.sh
@@ -8,5 +8,3 @@ set -euo pipefail
 #        1       7      39 ../helper-files/helper-2.txt
 #        3      19      92 ../helper-files/helper-3.txt
 #        5      30     151 total
-
-wc ../helper-files/*.txt
\ No newline at end of file

From b6324e43bb4a2e65ac52046b6bb4dd410b73fd35 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 13:14:21 +0100
Subject: [PATCH 12/23] remove changes on main branch

---
 number-systems/Part-1.md | 32 ++++++++++++++++----------------
 number-systems/Part-2.md | 12 +++++-------
 2 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/number-systems/Part-1.md b/number-systems/Part-1.md
index 68b77ea0b..d8f9c290e 100644
--- a/number-systems/Part-1.md
+++ b/number-systems/Part-1.md
@@ -6,49 +6,49 @@ The goal of these exercises is for you to gain an intuition for binary numbers.
 
 The answers to these questions should be a number, either in binary, hex, or decimal.
 
-Q1: Convert the decimal number 14 to binary. 0,2,4,8,16,32,64,128,256
-Answer: 1110
+Q1: Convert the decimal number 14 to binary.
+Answer:
 
 Q2: Convert the binary number 101101 to decimal:
-Answer: 45
+Answer:
 
 Q3: Which is larger: 1000 or 0111?
-Answer: 1000
+Answer:
 
 Q4: Which is larger: 00100 or 01011?
-Answer: 01011
+Answer:
 
 Q5: What is 10101 + 01010?
-Answer: 11111
+Answer:
 
 Q6: What is 10001 + 10001?
-Answer: 100010
+Answer:
 
 Q7: What's the largest number you can store with 4 bits, if you want to be able to represent the number 0?
-Answer: 15
+Answer:
 
 Q8: How many bits would you need in order to store the numbers between 0 and 255 inclusive?
-Answer: 9
+Answer:
 
 Q9: How many bits would you need in order to store the numbers between 0 and 3 inclusive?
-Answer: 2
+Answer:
 
 Q10: How many bits would you need in order to store the numbers between 0 and 1000 inclusive?
-Answer: 10
+Answer:
 
 Q11: Convert the decimal number 14 to hex.
-Answer: E
+Answer:
  
 Q12: Convert the decimal number 386 to hex.
-Answer: 182
+Answer:
 
 Q13: Convert the hex number 386 to decimal.
-Answer: 902
+Answer:
 
 Q14: Convert the hex number B to decimal.
-Answer: 11
+Answer:
 
 Q15: If reading the byte 0x21 as a number, what decimal number would it mean?
-Answer: 33
+Answer:
 
 Q16: Continues in Part-2
diff --git a/number-systems/Part-2.md b/number-systems/Part-2.md
index 1fce42ee7..68b0933d9 100644
--- a/number-systems/Part-2.md
+++ b/number-systems/Part-2.md
@@ -7,18 +7,16 @@ The goal of these exercises is for you to gain an intuition for binary numbers.
 The answers to these questions will require a bit of explanation, not just a simple answer.
 
 Q16: How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...)?
-Answer: If there is just one 1 in a binary number, then it is a power of 2. This is because each bit represents a power of 2, so if there is just one 1 bit in a binary number, the value represents a power of 2.
+Answer:
 
 Q17: If reading the byte 0x21 as an ASCII character, what character would it mean?
-Answer: !
+Answer:
 
 Q18: If reading the byte 0x21 as a greyscale colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
-Answer: It represents 33, which is in the range of 0–255 from dark to light. This value represents a very dark grey.
+Answer:
 
 Q19: If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be?
-Answer:  three one-byte => 
-AA | 00 | FF ==> AA : 10 * 16 + 10 * 1 = 170 | 00 : 0 * 16 + 0 * 1 = 0 | FF : 15 * 16 + 15 * 1 = 255
-so it reperesnt 170, 0, 255
+Answer:
 
 Q20: If reading the bytes 0xAA00FF as an RGB colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
-Answer: AA => 170 Red,  00 => 0 green , FF : 255 is blue
+Answer:

From 31364b4bb140180269c9b2a8aaa009071f7f6e9a Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 13:48:49 +0100
Subject: [PATCH 13/23] update script-01 file to be unchaged on main branch

---
 individual-shell-tools/ls/script-01.sh | 1 -
 1 file changed, 1 deletion(-)

diff --git a/individual-shell-tools/ls/script-01.sh b/individual-shell-tools/ls/script-01.sh
index 754a44837..3e5cb6eed 100755
--- a/individual-shell-tools/ls/script-01.sh
+++ b/individual-shell-tools/ls/script-01.sh
@@ -12,5 +12,4 @@ if [[ "${script_dir}" != "$(pwd)" ]]; then
 fi
 
 # TODO: Write a command to list the files and folders in this directory.
-
 # The output should be a list of names including child-directory, script-01.sh, script-02.sh, and more.
\ No newline at end of file

From ebca147ad05ff59d69f3fe3f9bfc1ff824b6b812 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 28 Jul 2026 17:52:45 +0100
Subject: [PATCH 14/23] fix unwanted file chnage

---
 individual-shell-tools/ls/script-01.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/individual-shell-tools/ls/script-01.sh b/individual-shell-tools/ls/script-01.sh
index 3e5cb6eed..241b62f5e 100755
--- a/individual-shell-tools/ls/script-01.sh
+++ b/individual-shell-tools/ls/script-01.sh
@@ -12,4 +12,4 @@ if [[ "${script_dir}" != "$(pwd)" ]]; then
 fi
 
 # TODO: Write a command to list the files and folders in this directory.
-# The output should be a list of names including child-directory, script-01.sh, script-02.sh, and more.
\ No newline at end of file
+# The output should be a list of names including child-directory, script-01.sh, script-02.sh, and more.

From 61dafbb8810a01bdc0051acb636b6f237a06ed46 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Mon, 31 Aug 2026 23:55:45 +0100
Subject: [PATCH 15/23] exercise1:Type checking with mypy

---
 sprint5/Exercise1.py | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 sprint5/Exercise1.py

diff --git a/sprint5/Exercise1.py b/sprint5/Exercise1.py
new file mode 100644
index 000000000..a469128c4
--- /dev/null
+++ b/sprint5/Exercise1.py
@@ -0,0 +1,30 @@
+def open_account(balances: dict[str,int], name: str, amount: int) -> None:
+    balances[name] = amount
+
+def sum_balances(accounts: dict[str, int]) -> int:
+    total = 0
+    for name, pence in accounts.items():
+        print(f"{name} had balance {pence}")
+        total += pence
+    return total
+
+def format_pence_as_string(total_pence: int) -> str:
+    if total_pence < 100:
+        return f"{total_pence}p"
+    pounds = int(total_pence / 100)
+    pence = total_pence % 100
+    return f"£{pounds}.{pence:02d}"
+
+balances = {
+    "Sima": 700,
+    "Linn": 545,
+    "Georg": 831,
+}
+
+open_account(balances, "Tobi", 913)
+open_account(balances, "Olya", 713)
+
+total_pence = sum_balances(balances)
+total_string = format_pence_as_string(total_pence)
+
+print(f"The bank accounts total {total_string}")
\ No newline at end of file

From a4b84ee551044caf85e34cc32de61acfa4a23024 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Mon, 31 Aug 2026 23:56:20 +0100
Subject: [PATCH 16/23] exercise2: Classes and objects

---
 sprint5/Exercise2.py | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 sprint5/Exercise2.py

diff --git a/sprint5/Exercise2.py b/sprint5/Exercise2.py
new file mode 100644
index 000000000..71e2f8a2e
--- /dev/null
+++ b/sprint5/Exercise2.py
@@ -0,0 +1,22 @@
+class Person:
+  def __init__(self, name: str, age: int, preferred_operating_system: str):
+    self.name = name
+    self.age = age
+    self.preferred_operating_system = preferred_operating_system
+
+imran = Person("Imran", 22, "Ubuntu")
+print(imran.name)
+print(imran.age)
+print(imran.preferred_operating_system)
+
+
+eliza = Person("Eliza", 34, "Arch Linux")
+print(eliza.name)
+
+def is_adult(person: Person) -> bool:
+  return person.age >= 18
+
+print(is_adult(imran))
+
+ def get_address(person: Person) -> str:  #this returns an error
+  return person.address

From e98a5713424d9c00114eb4183010a06e70fbed78 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 1 Sep 2026 00:41:17 +0100
Subject: [PATCH 17/23] method exercise

---
 sprint5/Methods.py | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 sprint5/Methods.py

diff --git a/sprint5/Methods.py b/sprint5/Methods.py
new file mode 100644
index 000000000..32bf47c14
--- /dev/null
+++ b/sprint5/Methods.py
@@ -0,0 +1,29 @@
+from datetime import date
+
+
+class Person:
+  def __init__(self, name: str, date_of_birth: date, preferred_operating_system: str):
+    self.name = name
+    self.date_of_birth = date_of_birth
+    self.preferred_operating_system = preferred_operating_system
+
+  def is_adult(self) -> bool:
+    today = date.today()
+
+    age = today.year - self.date_of_birth.year
+
+    if (today.month, today.day) < (
+      self.date_of_birth.month,
+      self.date_of_birth.day
+    ):
+      age -= 1
+
+    return age >= 18
+
+imran = Person(
+  "Imran",
+  date(2000, 5, 10),
+  "Ubuntu"
+)
+
+print(imran.is_adult())
\ No newline at end of file

From aaf5689aabc3b8a84da487c29b3bd16473032634 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 1 Sep 2026 01:29:39 +0100
Subject: [PATCH 18/23] dataclasses exercise

---
 sprint5/dataclasses-example.py | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 sprint5/dataclasses-example.py

diff --git a/sprint5/dataclasses-example.py b/sprint5/dataclasses-example.py
new file mode 100644
index 000000000..a1f77f7dd
--- /dev/null
+++ b/sprint5/dataclasses-example.py
@@ -0,0 +1,32 @@
+from dataclasses import dataclass
+from datetime import date
+
+
+@dataclass(frozen=True)
+class Person:
+  name: str
+  date_of_birth: date
+  preferred_operating_system: str
+
+  def is_adult(self) -> bool:
+    today = date.today()
+
+    age = today.year - self.date_of_birth.year
+
+    if (today.month, today.day) < (
+      self.date_of_birth.month,
+      self.date_of_birth.day,
+    ):
+      age -= 1
+
+    return age >= 18
+
+
+imran = Person(
+  "Imran",
+  date(2000, 5, 10),
+  "Ubuntu"
+)
+
+print(imran)
+print(imran.is_adult())
\ No newline at end of file

From aa9fa7c364d95e444b6791ada056da02827dfaf4 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 1 Sep 2026 01:41:57 +0100
Subject: [PATCH 19/23] generics exercise

---
 sprint5/generics.py | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 sprint5/generics.py

diff --git a/sprint5/generics.py b/sprint5/generics.py
new file mode 100644
index 000000000..e660ec7c7
--- /dev/null
+++ b/sprint5/generics.py
@@ -0,0 +1,20 @@
+from dataclasses import dataclass
+from typing import List
+
+@dataclass(frozen=True)
+class Person:
+    name: str
+    age: int
+    children: List["Person"]
+
+fatma = Person(name="Fatma", age=10, children=[])
+aisha = Person(name="Aisha", age=5 ,children=[])
+
+imran = Person(name="Imran", age=40, children=[fatma, aisha])
+
+def print_family_tree(person: Person) -> None:
+    print(person.name)
+    for child in person.children:
+        print(f"- {child.name} ({child.age})")
+
+print_family_tree(imran)
\ No newline at end of file

From 200002b29771ff02c0882bc547577187f2bae6e8 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 1 Sep 2026 01:59:46 +0100
Subject: [PATCH 20/23] Type-guided refactorings exercise

---
 sprint5/type-guided-refactorings.py | 42 +++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 sprint5/type-guided-refactorings.py

diff --git a/sprint5/type-guided-refactorings.py b/sprint5/type-guided-refactorings.py
new file mode 100644
index 000000000..784ad68f4
--- /dev/null
+++ b/sprint5/type-guided-refactorings.py
@@ -0,0 +1,42 @@
+from dataclasses import dataclass
+from typing import List
+
+@dataclass(frozen=True)
+class Person:
+  name: str
+  age: int
+  preferred_operating_systems: List[str]
+
+
+@dataclass(frozen=True)
+class Laptop:
+  id: int
+  manufacturer: str
+  model: str
+  screen_size_in_inches: float
+  operating_system: str
+
+
+def find_possible_laptops(laptops: List[Laptop], person: Person) -> List[Laptop]:
+  possible_laptops = []
+  for laptop in laptops:
+    if laptop.operating_system in person.preferred_operating_systems:
+      possible_laptops.append(laptop)
+  return possible_laptops
+
+
+people = [
+  Person(name="Imran", age=22, preferred_operating_systems=["Ubuntu", "Arch Linux"]),
+  Person(name="Eliza", age=34, preferred_operating_systems=["Arch Linux"]),
+]
+
+laptops = [
+  Laptop(id=1, manufacturer="Dell", model="XPS", screen_size_in_inches=13, operating_system="Arch Linux"),
+  Laptop(id=2, manufacturer="Dell", model="XPS", screen_size_in_inches=15, operating_system="Ubuntu"),
+  Laptop(id=3, manufacturer="Dell", model="XPS", screen_size_in_inches=15, operating_system="ubuntu"),
+  Laptop(id=4, manufacturer="Apple", model="macBook", screen_size_in_inches=13, operating_system="macOS"),
+]
+
+for person in people:
+  possible_laptops = find_possible_laptops(laptops, person)
+  print(f"Possible laptops for {person.name}: {possible_laptops}")
\ No newline at end of file

From 2ba06cca19e48d0085c89822a367de7f54c07d54 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Tue, 1 Sep 2026 16:02:22 +0100
Subject: [PATCH 21/23] enums exercise

---
 sprint5/enums.py | 84 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 sprint5/enums.py

diff --git a/sprint5/enums.py b/sprint5/enums.py
new file mode 100644
index 000000000..9e8259c1d
--- /dev/null
+++ b/sprint5/enums.py
@@ -0,0 +1,84 @@
+from dataclasses import dataclass
+from enum import Enum
+import sys
+
+
+class OperatingSystem(Enum):
+  MACOS = "macOS"
+  ARCH = "Arch Linux"
+  UBUNTU = "Ubuntu"
+
+
+@dataclass(frozen=True)
+class Person:
+  name: str
+  age: int
+  preferred_operating_system: OperatingSystem
+
+
+@dataclass(frozen=True)
+class Laptop:
+  id: int
+  manufacturer: str
+  model: str
+  screen_size_in_inches: float
+  operating_system: OperatingSystem
+
+
+
+laptops = [
+  Laptop(1, "Dell", "XPS", 13, OperatingSystem.ARCH),
+  Laptop(2, "Dell", "XPS", 15, OperatingSystem.UBUNTU),
+  Laptop(3, "Dell", "XPS", 15, OperatingSystem.UBUNTU),
+  Laptop(4, "Apple", "MacBook", 13, OperatingSystem.MACOS),
+]
+
+
+name = input("What is your name? ")
+
+try:
+  age = int(input("What is your age? "))
+except ValueError:
+  print("Age must be a number.", file=sys.stderr)
+  sys.exit(1)
+
+
+try:
+  operating_system = input("What operating system do you prefer? ")
+  preferred_operating_system = OperatingSystem(operating_system)
+except ValueError:
+  print("That is not a valid operating system.", file=sys.stderr)
+  sys.exit(1)
+
+
+person = Person(
+  name,
+  age,
+  preferred_operating_system
+)
+
+number_of_laptops = 0
+
+for laptop in laptops:
+  if laptop.operating_system == person.preferred_operating_system:
+    number_of_laptops += 1
+
+
+print(
+  f"There are {number_of_laptops} "
+  f"{person.preferred_operating_system.value} laptops available."
+)
+
+for operating_system in OperatingSystem:
+  number_available = 0
+
+  for laptop in laptops:
+    if laptop.operating_system == operating_system:
+      number_available += 1
+
+  if number_available > number_of_laptops:
+    print(
+      f"You are more likely to get a laptop if you "
+      f"are willing to use {operating_system.value}."
+    )
+

From b3a54f362159254d438069fb473511325a588d15 Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Wed, 2 Sep 2026 00:10:44 +0100
Subject: [PATCH 22/23] Inheritance  exercise

---
 sprint5/Inheritance.py | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 sprint5/Inheritance.py

diff --git a/sprint5/Inheritance.py b/sprint5/Inheritance.py
new file mode 100644
index 000000000..c80f5448f
--- /dev/null
+++ b/sprint5/Inheritance.py
@@ -0,0 +1,38 @@
+class Parent:  
+  def __init__(self, first_name: str, last_name: str): 
+    self.first_name = first_name
+    self.last_name = last_name
+
+  def get_name(self) -> str:
+    return f"{self.first_name} {self.last_name}"
+
+
+class Child(Parent):
+  def __init__(self, first_name: str, last_name: str):
+    super().__init__(first_name, last_name)
+    self.previous_last_names = []
+
+  def change_last_name(self, last_name) -> None:
+    self.previous_last_names.append(self.last_name)
+    self.last_name = last_name
+
+  def get_full_name(self) -> str:
+    suffix = ""
+    if len(self.previous_last_names) > 0:
+      suffix = f" (née {self.previous_last_names[0]})"
+    return f"{self.first_name} {self.last_name}{suffix}"
+
+person1 = Child("Elizaveta", "Alekseeva")
+print("1",person1.get_name()) # It should print "Elizaveta Alekseeva"
+print("2",person1.get_full_name()) # It should print "Elizaveta Alekseeva"
+person1.change_last_name("Tyurina") # Changes the last name to "Tyurina"
+print("3",person1.get_name())# It should print "Elizaveta Alekseeva" # I was wrong here because the child's last_name has been changed to "Tyurina".
+print("4",person1.get_full_name())# I thought it would print "Elizaveta Alekseeva (née Tyurina)" 
+# I was wrong here again because I misunderstood how last_name and previous_last_names work.
+
+person2 = Parent("Elizaveta", "Alekseeva")
+print("5",person2.get_name()) # It should print "Elizaveta Alekseeva"
+print("6",person2.get_full_name())  # Returns an error because Parent doesn't have a get_full_name() method.
+person2.change_last_name("Tyurina") # Returns an error because Parent doesn't have a change_last_name() method.
+print("7",person2.get_name()) # It should print "Elizaveta Alekseeva"
+print(person2.get_full_name()) # returns an error again because Parent doesn't have a get_full_name() method.
\ No newline at end of file

From f828703d5a9ff81224d50f3aea46c3d73a55cdfa Mon Sep 17 00:00:00 2001
From: Boshra Mahmoudi <boshra@Boshras-MacBook-Pro-2.local>
Date: Thu, 3 Sep 2026 14:03:18 +0100
Subject: [PATCH 23/23] Improve code using Python built-in methods and floor
 division

---
 sprint5/Exercise1.py | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/sprint5/Exercise1.py b/sprint5/Exercise1.py
index a469128c4..898aab966 100644
--- a/sprint5/Exercise1.py
+++ b/sprint5/Exercise1.py
@@ -2,17 +2,15 @@ def open_account(balances: dict[str,int], name: str, amount: int) -> None:
     balances[name] = amount
 
 def sum_balances(accounts: dict[str, int]) -> int:
-    total = 0
     for name, pence in accounts.items():
         print(f"{name} had balance {pence}")
-        total += pence
-    return total
+    return sum(accounts.values())
 
 def format_pence_as_string(total_pence: int) -> str:
     if total_pence < 100:
         return f"{total_pence}p"
-    pounds = int(total_pence / 100)
-    pence = total_pence % 100
+    pounds = total_pence // 100
+        pence = total_pence % 100
     return f"£{pounds}.{pence:02d}"
 
 balances = {