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

A young engineer decides to save $240 per year toward retirement in 40 years.

1. If he invests this sum at the end of every year at 9%, then how much will be accumulated by retirement time?
2. If by astute investing the interest rate could be raised to 12%, then what sum could be saved?
3. 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?
4. In part (c), then what annual effective interest rate is being earned?