Determine all possible values of a 5-digit positive integer N, such that:
- The first two digits of N, read as a two digit number, are three times the third digit, and:
- The last two digits of N (read as a two digit number) are twice the third digit, and:
- The sum of all the digits of N is 27.
Prove that there are no others.
(In reply to
Proof by Charlie)
The middle digit must be a multiple of 3 for the sum of digits to be a multiple of 9.
You only need to check 3, 6 and 9
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Posted by Jer
on 2014-04-24 01:32:35 |