text: #include <stdio.h>
  #include <stdlib.h>
  
  float rate(float hours) {
      float f;
  
      if (hours < 10.0) f = 1.5 * hours;      //rate 1
      else if (hours < 15.0) f = 2.0 * hours; //rate 2
      else f = 2.5 * hours;                   //rate 3
  
      return f;
  }
  
  int main() {
      float hours, cost;
  
      hours = 10.1;
      cost = rate(hours);
      printf("Your bill for %f hours usage is $%f\n", hours, cost);
  
      exit(0);
  }