A young engineer decides to save $240 per year toward retirement in 40 years.
If he invests this sum at the end of every year at 9%, then how much will be accumulated by retirement time?
If by astute investing the interest rate could be raised to 12%, then what sum could be saved?
If he deposits one fourth of this annual amount each quarter ($60 per quarter) in an interest-bearing account earning a nominal annual interest rate of 12%, compounded quarterly, how much could be saved by retirement time?