Determine the (non-leading zero) 3-digit positive integer N such that the product of the digits of N is equal to N/5.
Source: Adapted from a problem appearing in a German Mathematical Olympiad.
*** Computer solutions are welcome, but an analytical solution is preferred.
a*b*c = (100a + 10b + c)/5 < 999/5 < 200 so a=1.
c=5 as noted, then 25b = 10b + 105 and b=7.
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Posted by xdog
on 2022-10-05 20:13:00 |