Four friends decide to have a party every Saturday. They decide to pool the money to spend on the parties. The table below shows the maximum amount each friend is willing to contribute to each party. Number of parties First party Second party Third party Fourth party 4 2 1 Peter $250 $200 $135 $60 3 Mary $340 $270 $80 $100 Kate If the cost of each party is $225, how many parties should they have to maximize total surplus? $120 $100 $70 $25 Jacob $215 $160 $100 $40