20. Tony and Patty produce skis and snowboards. The tables show their production possibilities. Each week, Tony produces 5 snowboards and 40 skis; Patty produces 10 snowboards and 5 skis. Tony's Production Possibilities Snowboards (units per week) Skis (units per week) 15 and 20 10 and 30 5 and 40 50 O 20 10 Patty's Production Possibilities Snowboards (units per week) Skis (units per week) 10 a. Who has a comparative advantage in producing (i) snowboards and (ii) skis? b. If Tony and Patty specialize and trade 1 snowboard for 1 ski, what are the gains from trade