Red and Black CardsProbability puzzles require you to weigh all the possibilities and pick the most likely outcome.
You have two cards, one red on both sides, one red on one side and black on the other. You reach into a hat and pull out one card, viewing only the top. It is red. What`s the probability that the other side is red?
AnswerThe probability that it is red is 2/3. If you think of the 3 red sides as labeled r1, r2, and r3, then 2 of the 3 times you see a red card, it will be red on the other side.
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