Posted by Kat on Monday, February 14, 2011 at 2:49am.
You have a bag of lots of red and white marbles. In the worst case, how many would you have to pull out to get two marbles of the same color? Four? Generalize by finding a formula for predicting the maximum number of marbles that you would have to pull out to get the same color of any amount you desire.
What if there were three colors of marbles in the bag, how many would you have to pull out to get two marbles of the same color? Three? Four? Generalize by finding a formula for predicting the number of marbles you would have to pull out to get the same color of any amount you desire.

math  PsyDAG, Monday, February 14, 2011 at 9:08am
Asume you get one of each color in the first draws. Then the next draw would certainly repeat one of the colors.
That should start you out in getting your formula. Let c = number of colors and n = number of marbles you want of the same color. 
math  Kat, Monday, February 14, 2011 at 10:08am
but its in the WORST case scenario
You didn't really answer the question at all