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With or without (Posted on 2021-03-22)

Let N be a randomly selected number between 1 and 999,999 inclusive.

Is it more likely that N contains the digit 1 or that it does not?

No Solution Yet Submitted by Ady TZIDON

Rating: 4.5000 (2 votes)

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Solution

| Comment 1 of 5

Of the 10^6 - 1=999999 numbers from which N is selected, 9^6=531441 will contain a digit that is not 1 in each place. This is a bit over half.

It is more likely that N does not contain a 1.

(Had the upper bound on N contained more 9's the answer would be the opposite. 9^7=4792969)

Posted by Jer on 2021-03-22 07:58:27

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