A single coin is tossed once. If a head appears you win $2 and if a tail appears you lose $1.
Expected win for 1 game
E(W) = 0.5 * 2 + 0.5*(-1) = 0.5
How much would you expect to win from playing this game three times?
E(W playing 3 times) = 3*0.5 = 1.5