Two Coins
Braingle.com
on
Published in Brain Teasers
Suppose I flip two coins, without letting you see the outcome, and I tell you that at least one of the coins came up heads, what is the probability that the other coin is also heads?
Solution:
1/3.
For two coins, there are four possible outcomes: HH, HT, TH, TT, since we know that at least one was a head, we can eliminate TT. Of the remaining three possibilities, only 1 allows the second head: HH.
Today's brain teaser courtesy of Braingle.com.
