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 That's a lotta numbers! (Posted on 2006-04-14)
Consider all nine-digit numbers consisting of one each of the digits 1 through 9.

What is the sum of these numbers?

 See The Solution Submitted by Jer Rating: 3.2500 (4 votes)

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 Is this it? | Comment 2 of 10 |
(In reply to Some Hints For Solving The Problem by K Sengupta)

OK, so there are 9! permutations of digits.  In each place, 1/9 (40320) of them will be a 9, 1/9 will be an 8...etc.

The sum of the digits 1-9 is 45, so I'm guessing the sum we're looking for is:

`     4500000000      450000000       45000000        4500000         450000           45000           4500            450     +       45     ----------     4999999995     x    40320     ----------201599999798400`
`Did I screw that up?`
` `

 Posted by tomarken on 2006-04-14 11:49:48

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