Determine the probability that none of the cards drawn is a Diamond.
Chris,
Probability is usually defined as the number of desired outcomes divided by the total number of possible outcomes. In this case a deck of cards has 52 possible outcomes (1 for each card), 13 of which are diamonds or 52-13=39 not-diamonds, so the probability that I would draw a diamond on the first draw is 1/4 (13/52), and the probability that I do not draw a diamond is 3/4 (39/52).
So if I do not draw a diamond on the first draw (39/52) times, because there is no replacement, the odds that I do not draw a diamond again is 38/51; and again, after the second draw, the odds that I do not draw a diamond again is 37/50. Because these are dependent events, we have to multiply these three numbers together. Or (39*38*37)/(52*51*50).
I hope this helps. John