If I put nine pieces of paper, with a digit from 19 written on each one, into a hat, and pull 3 out without replacement, what is the likelihood that I will select three numbers that result in a winning tictactoe?
1  2  3
++
4  5  6
++
7  8  9
There are 8 different winning lines which can be made, each line can be completed in any one of 6 ways. The total combination of winning ways is 48. The total number of ways in which 3 selections can be made from 9 is 9!/(93)! = 504. The answer is therefore 84/8

Posted by Mark
on 20041004 09:05:19 