This year Randy paid $28,300 of interest on his residence. (Randy borrowed $454,000 to buy his residence, which is currently worth $504,000.) Randy also paid $2,600 of interest on his car loan and $4,350 of margin interest to his stockbroker (investment interest expense). How much of this interest expense can Randy deduct as an itemized deduction under the following circumstances?

a. Randy received $2,280 of interest this year and no other investment income or expenses. His AGI is $75,000. What is the interest deductible

b. Randy had no investment income this year, and his AGI is $75,000. What is the interest deductible