There are four balls in a hat: a blue one, a white one, and two red ones. Now I draw simultaneously two balls, look at them, and announce that at least one of them is red.

What is the chance that the other is red as well?

(In reply to I agree with Brian by Steve Herman)

But the fact that the one he chose to talk about happened to be red is a sampling that increases the likelihood of both being red. 

Posted by Charlie on 2017-05-19 23:01:06