public class Investment {
  private double myBalance, myInterest;
  
  public Investment(double balance, double interest) {
    myBalance = balance;
    myInterest = interest;
  }
  
  public double getBalance() {
    return myBalance;
  }
  
  public double getInterest() {
    return myInterest;
  }
  
  public int yearsForBalance(double target) {
    int years = 0;
    double balance = myBalance; 
    while ( balance < target ) {
      years++; // or years += 1;
      double interest = balance * myInterest;
      balance += interest;  
    }
    return years;
  }
  
  public double balanceForYears(int years) {
    int year;
    double balance = myBalance;
    for ( year = 1; year <= years; year++ ) {
      double interest = balance * myInterest;
      balance += interest;
    }
    return balance;
  }
  
}