There are 10 different hats, what is the probability that if I got 4 of them that I would get at least 2 the same?
Would it be $\displaystyle 1/10 * 1/9 * 1/8 * 1/7$?
Thanks in advance.
Maybe this is wrong but I think it's...
1-Probability(all hats are different)
So you get your first hat with prob 1.
The prob that the second one is different is 9/10
The prob that the third one is different is 8/10
The prob that the fourth one is different is 7/10
So 1-Probability(all hats are different) = 1-(9/10*8/10*7/10) = 0.496.