There are 100 opaque vases in front of you, each containing 99 balls. In 99 of the vases, one ball is red and the remainder of the balls are black. However, in the last vase, all 99 balls are red. You pick one of the vases randomly and happen to draw a red ball. You then discard the ball. The next ball you draw from the same vase is most likely to be:
A. Red
B. Black
C. Equally likely
Scroll down for a clue and further down for the answer.
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Clue: Note that there are 99 balls in each vase, not 100.
Scroll down for the answer.
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Answer: C. Equally likely.
The probability of picking the vase containing the red balls is equal to the probability of picking one of the other 99 vases and then a red ball. In the first scenario, there is a 100% probability that the next ball you pick is red. In the second scenario, there is a 100% probability that the next ball you pick is black.
Puzzle a Day 