ATM.java

public class ATM{
  // Static variables
  public static int totalMoney = 0;
  public static int numATMs = 0;

  // Instance variables
  public int money;

  public ATM(int inputMoney){
    this.money = inputMoney;
    numATMs += 1;
    totalMoney += inputMoney;
  }

  public void withdrawMoney(int amountToWithdraw){
    if(amountToWithdraw <= this.money){
      this.money -= amountToWithdraw;
      totalMoney -= amountToWithdraw;
    }
  }

  public static void averageMoney(){
    System.out.println(totalMoney / numATMs);
  }

  public static void main(String[] args){

    System.out.println("Total number of ATMs: " + ATM.numATMs); 
    ATM firstATM = new ATM(1000);
    ATM secondATM = new ATM(500);
    System.out.println("Total number of ATMs: " + ATM.numATMs); 

    System.out.println("Total amount of money in all ATMs: " + ATM.totalMoney);  
    firstATM.withdrawMoney(500);
    secondATM.withdrawMoney(200);
    System.out.println("Total amount of money in all ATMs: " + ATM.totalMoney);    

    // Call averageMoney() here
    ATM.averageMoney();
  }

}