Write a C function (NOT A COMPLETE PROGRAM) which uses the RETURNstatement to calculate and return the total cost for purchasing books (quantity * bookcost). The parameter needed is the quantity of books wanted. If 20 or fewer books are wanted, then each book costs $23.45. If 21 to 100 books are wanted, then each book costs $21.11. If more than 100 books arewanted, then each book costs $18.75. Please assume that number of books passed to your function is positive.

int calculate_cost(int quantity) {

   double cost = 0;

   if (quantity <= 20)

       cost = quantity * 23.45;

   else if (quantity >= 21 && quantity <= 100)

       cost = quantity * 21.11;

   else if (quantity > 100)

       cost = quantity * 18.75;

   return cost;

}

Explanation:

Create a function called calculate_cost that takes one parameter, quantity

Initialize the cost as 0

Check the quantity using if else structure. Depending on the quantity passed, calculate the cost. For example, if the quantity is 10, the cost will be $234.5

Return the cost