Suppose that Peter Minuit did not become the first New York real estate tycoon but instead had invested his $24 at a 5% interest rate in New Amsterdam Savings Bank. What would have been the balance in his account after 5 years? 50 years?

I know that the answer is $24(1 + 5%)^50= $103.7. But can someone explain how they get $103.7 for 50 year?