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Brain Teaser #63 |
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| Nov5-03, 11:31 PM | #1 |
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Brain Teaser #63
What is the sum of all the numbers formed by taking each of the digits 2,3,5,6 and 8 once?
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| Nov5-03, 11:36 PM | #2 |
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haha, maybe later.
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| Nov6-03, 12:02 AM | #3 |
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6399936
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| Nov6-03, 12:29 AM | #5 |
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Hmm...combinatorics.
2 3 5 6 8 There are: (5)*(5-1)*(5-2)*(5-3)*(5-4) or 5*4*3*2*1 = 120 permutations for the above set of numbers. One set of numbers add up to: 2+3+5+6+8 = 24. So, the sum of all numbers formed from 120 permutations is: 120*24 = 2880. |
| Nov6-03, 12:32 AM | #6 |
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If I answered the right question, for all of the 5-digit numbers you can make, each digit appears 24 times in each column, so you can write:
24*(22222+33333+55555+66666+88888)=6399936 Edit: Oh, I thought it was the sum of the numbers made by the combinations, not the sum of their digits. |
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