4. This year, Benjamin Hassell paid $20,000 of interest on a mortgage on his home (Benjamin borrowed $600,000 in 2015 to buy the residence and it is currently worth $1,000,000), $12,000 on a $150,000 home-equity loan on his home, and $10,000 of interest on a mortgage on his vacation home (loan of $300,000; home purchased for $400,000 in 2016; home is not rented out at any time). How much interest expense can Benjamin deduct as an itemized deduction? Please show all workings.