I'm posting one puzzle, riddle, math, or statistical problem a day. Try to answer each one and post your answers in the comments section. I'll post the answer the next day. Even if you have the same answer as someone else, feel free to put up your answer, too!
Monday, October 12, 2009
Marbles in a Box, Marbles with a Fox
We have six white marbles, one red marble and four black marbles in a box. What would be the smallest number of marbles that we need to take out of the box to guarantee that we get three of the same color?