Lenore, a single taxpayer with adjusted gross income of $67,000, is covered by her employer's pension plan. She makes a $5,500 contribution to her IRA during the current year.

a. How much of the contribution can Lenore deduct?

b. Assume the same facts as above, except that Lenore's adjusted gross income is $77,000.

c. Assume that Lenore is married to Lathrop who has no income, and their combined adjusted gross income is $130,000. Lathrop is not covered by any retirement plan. What are Lenore and Lathrop's maximum deductible IRA contribution?