Simple & Compounding Interest
posted by Need Help!!! .
Suppose Kevin and Jill both deposit $4000 into their personal accounts. If Kevin’s account earns 5% simple interest annually and Jill’s earns 5% interest compounded annually, how much will each account balance show at the end of 5 years? Calculate the difference between each account.

If $640 is invested in an account that earns annual interest of 3.5%, compounded semiannually, what will the account balance be after 4 years? (Round your answer to the nearest cent.)

sierra deposits $500 into a new savings account that earns 5% interest compounded annually. if sierra makes an additional deposits or withdrawals, how many years will it take for the amount in her account to double?