On march 1, roxanne acquires a house for $160,000. she pays $20,000 down and borrows the remaining $140,000 by obtaining a 15-year mortgage. roxanne pays $3,500 in closing costs and $2,500 in points in purchasing the house. during the year, she pays $10,300 of interest on her mortgage. a. roxanne's allowable interest deduction for the year is $. b. how would your answer to the above question change if roxanne already owned her home and the points paid on march 1 were for a 15-year mortgage to refinance her existing mortgage. her total allowable home mortgage interest deduction is $ .