Word Problem.
posted by Lyndse .
A game is played by flipping three coins. If all three coins land heads up you win $15. If two coins lands heads up you win $5. If one coin lands heads up you win $2. If no coins land heads up you win nothing. If you play $4 to play, what are your expected winnings?

Prob (HHH) = 1/8
expected value = (1/8)(15) = 1.875
prob(HHT or HTH or THH) 3/8
expected winnings = (3/8)(5) = 1 .875
prob(HTT or THT or TTH) = 3/8
expected winnings = (3/8)(2) = .75
prob( TTT) = 1/8
expected winning = 0
total expected winnings = 4.5
to play the game costs $4
expected winnings = $0.50
Bet you won't see that game in Vegas. 
Thank you Reiny.