Bob places $$1,000$ a year in his IRA for $10$ years and then invests $$2,000$ a year for the next $10$ years. Mary places $$2,000$ a year in her IRA for $10$ years and then invests $$1,000$ a year for the next $10$ years. They both have invested $$30,000.$ If they earn $8$ percent annually, how much more will Mary have earned than Bob at the end of $20$ years?

Please show how to solve using a BAII Plus calculator!

Answer:

Bob: $$60,247$

Mary: $$77,037$

Difference: $$16,790$