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zorro
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Homework Statement
Seven chits are numbered 1 to 7. Three are drawn one by one with replacements. The probability that the least number on any selected chit is 5, is?
The Attempt at a Solution
We require 5 to be present on atleast one of the three chits and no number should be less than 5.
So required probability = P(three times 5) + P(two times 5) + P(one time 5)
= (1/7)3 + 1/7*1/7*2/7*3 + 1/7*2/7*2/7*3=19/343
The answer given is
(3/7)3