This year Randy paid $29,200 of interest on his residence. (Randy borrowed $466,000 to buy his residence, which is currently worth $516,000.) Randy also paid $2,900 of interest on his car loan and $4,800 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 $2,520 of interest this year and no other investment income or expenses. His AGI is $75,000.

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