ANSWER:
#include <stdio.h>
#define PAYRATE 10 //basic pay rate per hour
#define OVERTIME 15 //in excess of 40 hours a week
int NetPay(int hours);
int main()
{
 int userWeeklyHours;
 printf("Please enter your total weekly working hours: \n");
 scanf("%d", &userWeeklyHours);// get the user weekly hours
 NetPay(userWeeklyHours);
 return 0;
}
int NetPay(int hours)// implementing the function to calculate total pay, total taxes, and net pay
{
 int firstRate, secondRate, restOfRate, secondAmount, rest, payAfterTax, payedBeforeTax, overHours;
 if (hours > 40)
 {
 overHours = hours - 40;
 payedBeforeTax = (40 * PAYRATE) + (overHours * OVERTIME);
 }
 else
 payedBeforeTax = hours * PAYRATE;//defining the user first paycheck before taxes 
 if (payedBeforeTax <= 300)//paying only first rate case
 {
 firstRate = payedBeforeTax*0.15;
 payAfterTax =payedBeforeTax - firstRate;
 printf("your total gross is %d, your taxes to pay are %d, your net pay is %d", payedBeforeTax, firstRate, payAfterTax);
 }
 else if (payedBeforeTax > 300 && payedBeforeTax <= 450)//paying first and second rate
 {
 secondAmount = payedBeforeTax - 300;
 firstRate = (payedBeforeTax - secondAmount) * 0.15;
 secondRate = secondAmount * 0.20;
 payAfterTax = payedBeforeTax - (firstRate + secondRate);
 printf("your total gross is %d, your taxes to pay are %d, your net pay is %d", payedBeforeTax, firstRate + secondRate, payAfterTax);
 }
 else if (payedBeforeTax > 450)// paying all rates 
 {
 rest = payedBeforeTax - 450;
 secondAmount = (payedBeforeTax - 300) - rest;
 firstRate = (payedBeforeTax - (rest + secondAmount)) * 0.15;
 secondRate = secondAmount * 0.20;
 restOfRate = rest * 0.25;
 payAfterTax = payedBeforeTax - (firstRate + secondRate + restOfRate);
 printf("your total gross is %d, your taxes to pay are %d, your net pay is %d", payedBeforeTax, firstRate + secondRate + restOfRate, payAfterTax);
 }
 return payAfterTax;
}