Walter, a single taxpayer, purchased a limited partnership interest in a tax shelter in 1992. He also acquired a rental house in 2018, which he actively manages. During 2018, Walter’s share of the partnership’s losses was $30,000, and his rental house generated $20,000 in losses. Walter’s modified adjusted gross income before passive losses is $130,000. 

a. Calculate the amount of Walter’s allowable deduction for rental house activities for 2018. 

b. Calculate the amount of Walter’s allowable deduction for the partnership losses for 2018. 

c. What may be done with the unused losses, if anything?