Given a principal amount, an annual interest rate in percent, and a number of years, return the simple interest earned, formatted with two decimal places. Simple interestSimple InterestInterest charged only on the original amount: principal × rate × years / 100. It does not compound. grows by the same amount every year, so the formula is a single line. The interesting part is choosing variable types. The product can reach five billion — too big for an int — and money should not pick up rounding errors. The first solution uses a double; the second keeps everything as whole numbers by counting in hundredths, which is exact.