diff --git a/st40.c b/st40.c
new file mode 100644
index 0000000..87c2ef8
--- /dev/null
+++ b/st40.c
@@ -0,0 +1,50 @@
+#include<stdio.h>
+int main()
+{
+intlocks,stocks,barrels,sales,flag=0;
+float commission;
+printf("Enter the total number of locks\n");
+scanf("%d",&locks);
+printf("Enter the total number of stocks\n");
+scanf("%d",&stocks);
+printf("Enter the total number of barrels\n");
+scanf("%d",&barrels);
+if((locks<=0) || (locks>70))
+{
+flag=1;
+printf("Locks out of range\n");
+}
+if((stocks<=0) || (stocks>80))
+{
+flag=1;
+printf("Stocks out of range\n");
+}
+if((barrels<=0) || (barrels>90))
+{
+flag=1;
+printf("Barrels out of range\n");
+}
+if(flag == 1)
+{
+printf("Invalid input\n");
+return 0;
+}
+sales= locks*45 + stocks*30 + barrels*25;
+if(sales <= 1000)
+{
+commission = 0.10 * sales;
+}
+else if(sales <= 1800)
+{
+commission = 0.10 * 1000;
+commission = commission + (0.15 * (sales - 1000));
+}
+else
+{
+commission = 0.10 * 1000;
+commission = commission + (0.15 * 800);
+commission = commission + (0.20 * (sales - 1800));
+}
+printf("Total sales: %d and Commission: %f\n",sales,commission);
+return 0;
+}