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 $