The product of 3 brothers' ages is 567. Two are twins.

How old is the other one?

The prime factorization of 567 is 3×3×3×3×7.

Since there are four factors of three, there are three ways mathematically to multiply three numbers, two of which are equal, to get 567:

1×1×567 = 567
3×3×63 = 567
9×9×7 = 567

Of these, the second is possible, but the third is the only really plausible answer, and probably what we are looking for.
The twins are 9, and the other brother is 7.

Perhaps, to further eliminate the other possibilites other than by inspection, it could have been said that the twins were older than the other brother, or something like that.

Posted by DJ on 2003-08-14 08:05:05