1. The problem statement, all variables and given/known data there are 30 red balls, 30 white balls, and 30 blue balls in a container. you draw 10 of them, without replacement. what is the probability that at least one color won't be selected. 2. Relevant equations 3. The attempt at a solution i've been working on this one for too long. someone gave me a solution, but after i thought about it i realized it didn't work if you don't replace. the best solution i could come up with is the following: for the total number of possibilities, since i can draw 90 for my first, 89 for my second and so on, i have 90!/80! ways of drawing balls. for the number which exclude one color, i have 90*89 (and here i have to reduce the pool by 30 so those don't get selected)*58*57*...51. but then someone pointed out that order doesn't matter, and i wasn't sure if there was something i could multiply this number by to make order irrelevant. as always, i'm looking for hints more than a solution. also, variations on this problem would be cool too. i'm here to learn, people!