The gamblerDiscrete Mathematics Level 3
A gambler shows you a box with 5 white and 2 black marbles in it. All the marbles are identical except for their color. He invites you to draw without replacement 3 marbles from the box, while you are blindfolded, and you lose if you draw a black marble.
If you lose $10 for losing the game, how much should you paid for winning it for your mathematical expectation to be zero (i.e., making it a fair game)?