A card is drawn at random from a deck consisting of cards numbered 2 through 10. A player wins 1 dollar if the number on the card is odd and loses 1 dollar if the number if even. What is the expected value of his winnings?
9 possible cards 5 even and 4 odd
\(E(X) = 1*(4/9) − 1*(5/9) = −1/9\)
So the expected value is losing $0.11.