The product of 3 brothers' ages is 567. Two are twins.
How old is the other one?
Let the ages of the brothers be A, A, and B.
AxAxB=567
B=567/(AxA)
There AxA, a square number, must divide evenly into 567. But 567=3x3x3x3x7, so clearly 9 is the only square number that divides into 567. Therefore A=3 and B=63
The "other one" is 63 years old. The twins are 3.
(To the objection that this in impossible...NOT SO. The artist Picasso was conceiving children in his 90's. So Picasso could have children with such disparate ages as 63 and 3.)