A couple thinking about retirement decide to put aside $4,000 each year in a savings plan that earns 7% interest annually. In 8 years they will receive a gift of $12,000 that also can be invested at the same rate of interest.

(a) How much money will they have accumulated 30 years from now? (

b) If their goal is to retire with $900,000 of savings, how much extra do they need to save every year?