(a) A sum of $12 000 is invested at 4% annual interest. What will this amount have grown to after 15 years?
(b) How much should you have deposited in a bank account 5 years ago in order to have $50 000 today, given that the interest rate has been 5% per year over the period?
(c) A credit card is offered with interest on the outstanding balance charged at 2% per month. What is the effective annual rate of interest?