Answer the following independent questions with respect to Traditional and Roth IRA's for 2020.

a. Diego, age 41, earns a salary of $28,000 and is not an active participant in any other qualified plan. His wife, Allie, has no earned income. What is the maximum total combined deductible contribution to their IRAs? Diego wants to contribute as much as possible to his own and his wife's IRA.

b. Leo's employer makes a contribution of $4,500 to Leo's simplified employee pension plan. If Leo is single, has earned income of $30,000, and has AGI of $40,000, what amount if any can he contribute to an IRA?

c. Olsen establishes a Roth IRA at age 37 and contributes a total of $89,600 over 28 years. The account is now worth $112,000. How much of these funds may Olsen withdraw tax-free?