Two engineers are planning for retirement. They will each retire at age 75. Engineer 1 (E1) will start saving $500 per month at age 25. Engineer 2 (E2) does not plan to start saving for retirement until the age of 50 but will save $1000 per month (twice as much as E1 for half as long). They will each earn an interest rate of 10% per year compounded monthly.

a. How much does each engineer have at retirement?

b. They each invested $300,000 over their investment periods. Why did E1 end up with more money?

c. How much would E2 needed to save per month to have the same amount of money at retirement as E1?