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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)

Comments: ( Back to comment list | You must be logged in to post comments.)

to be more exact

| Comment 4 of 5 |

The number of numbers that do not contain a 1 is

9^6 - 1 = 531440

That's out of the total of 999,999 numbers, so the probability of not having a 1 is

531440/999999 ~= 0.531440531440531

The probability of having at least one 1 is then 0.468559468559..., and the number is therefore more likely not to have a 1 than to have it.

Posted by Charlie on 2021-03-22 10:22:51

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