The probability of selecting one number that is not 8 from a pool of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 (10 numbers) is 9/10.
The probability of selecting one number that is not 8 from a pool of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 (10 numbers) for each digit of a four digit number XXXX (where X does not equal 8) is (9/10)^4.
The probability of selecting a four digit number which contains at least a number 8 in any of its digit is 1 - (9/10)^4
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发表于 2010-11-19 03:54:06
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