Math Word Problem?

Question

1. Nancy invests $100 in one account for 10 years at a 9% interest rate compounded annually, and she invests $150 in an account for 10 years at a 6% interest rate compounded semi-annually. How much money will she have in the accounts after 10 years?

Answer 1

You need to find 9% of $100 for the first year, which is $9. Take that and add it to the $100, calculate 9% of $109 for the second year, do this up until the 10th year.

Answer 2

It's 100 * 1.09^10 + 150 * 1.03^20. The latter term assumes that semiannual compounding applies half the interest rate twice a year. See the ref.