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| Last digit counts (Posted on 2014-07-23) |
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How many 4-digit numbers are there such that their last digit is either sum or product of the first three?
1. EX: 1258 and 4090 qualify.
2. No leading zeroes.
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Submitted by Ady TZIDON
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No Rating
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Solution:
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(Hide)
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215 (product)+ 165(sum)-6(both)= 374
Charlie's comment lists all the 374. |
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