Chapter 5 Exercise 39, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

*5.39 (Financial application: find the sales amount) You have just started a sales job in a department store. Your pay consists of a base salary and a commission. The base salary is $5,000. The scheme shown below is used to determine the commission rate.
Sales Amount Commission Rate
$0.01–$5,000 8 percent
$5,000.01–$10,000 10 percent
$10,000.01 and above 12 percent

Note that this is a graduated rate. The rate for the first $5,000 is at 8%, the next $5000 is at 10%, and the rest is at 12%. If the sales amount is 25,000, the commission is 5,000 * 8% + 5,000 * 10% + 15,000 * 12% = 2,700. Your goal is to earn $30,000 a year. Write a program that finds the minimum sales you have to generate in order to make $30,000.

import java.util.Scanner;
//This is probably not exactly what the question asks for.
public class ProgrammingEx5_39 {
 
 public static void main(String[] args) {
 
  Scanner input = new Scanner(System.in);
  System.out.print("Enter commission amount:");
  double commissionSought = input.nextDouble();
  double sale;
 
  if (commissionSought <= 400) {
   sale = commissionSought / 0.08;
 
  } else if (commissionSought <= 900) {
   sale = (commissionSought - 400) / 0.1 + 5000;
  } else {
   sale = (commissionSought - 900) / 0.12 + 10000;
  }
 
  System.out.println("The sale you need to generate is " + sale);
 
 }
 
}