C(100,6) -------- = .014465141 C(200,6) Or you can look at it this way. Suppose the gumballs come out one at a time. The probability that the 1st one is green is= The probability that the 2nd one is green is The probability that the 3rd one is green is = The probability that the 4th one is green is The probability that the 5th one is green is = The probability that the 6th one is green is = Desired probability = = = = .014465141 Edwin