1 // Exercise 3.3 Calculate a discounted price 2  3 // I interpreted this exercise as implying that the 10% applies to items 31 to 50 4 // and the 15% applies to items in excess of 50. 5 // That is, you don‘t get 15% discount on the whole price when you order 51 items. 6  7 // There is more than one way of doing this so different is not necessarily wrong. 8  9 #include <stdio.h>10 11 int main(void)12 {13   const int level1 = 30;               // Quantity over this level are at discount114   const int level2 = 50;               // Quantity over this level are at discount215   const double discount1 = 0.10;       // 10% discount16   const double discount2 = 0.15;       // 15% discount17   const double unit_price = 5.0;       // Basic unit price18   int quantity = 0;19   int qty_full_price = 0;              // 0 to 30 at full price20   int qty_level1 = 0;                  // 31 to 50 at level1 price21   int qty_level2 = 0;                  // Over 50 at level2 price22   printf("Enter the quantity that you require: ");23   scanf("%d", &quantity);24  25   if(quantity > 50)                     // Quantity over 5026   {27     qty_full_price = level1;28     qty_level1 = level2 - level1;29     qty_level2 = quantity - level2;30   }31   else if(quantity > 30)                // Quantity is from 30 to 5032   {33     qty_full_price = level1;34     qty_level1 = quantity - level1;35   }36   else37     qty_full_price = quantity;38 39   printf("The total price for %d items is $%.2lf\n", quantity,40     unit_price*(qty_full_price + (1.0 - discount1)*qty_level1 + (1.0 - discount2)*qty_level2));41   return 0;42 }