# C - Write program to calculate price based on quantity

## Requirements

Calculate the price for a quantity entered by user.

The unit price is \$5 and there is a discount of 10 percent for quantities over 30 and a 15 percent discount for quantities over 50.

## Hint

Use if statement to check quantity.

## Demo

```#include <stdio.h>

int main(void)
{
const int level1 = 30;               // Quantity over this level are at discount1
const int level2 = 50;               // Quantity over this level are at discount2
const double discount1 = 0.10;       // 10% discount
const double discount2 = 0.15;       // 15% discount
const double unit_price = 5.0;       // Basic unit price
int quantity = 0;
int total = 0;              // 0 to 30 at full price
int a1 = 0;                  // 31 to 50 at level1 price
int a2 = 0;                  // Over 50 at level2 price

printf("Enter the quantity that you require: ");
scanf("%d", &quantity);

if (quantity > 50)                     // Quantity over 50
{/*from   w w w  . java  2  s  .  c o  m*/
total = level1;
a1 = level2 - level1;
a2 = quantity - level2;
}
else if (quantity > 30)                // Quantity is from 30 to 50
{
total = level1;
a1 = quantity - level1;
}
else
total = quantity;

printf("The total price for %d items is \$%.2lf\n", quantity,
unit_price*(total + (1.0 - discount1)*a1 + (1.0 - discount2)*a2));
return 0;
}
```