There are infinitely many pairs of numbers whose sum equals their product.

However, there is only one solution to the equation below, in which each letter stands for a single, distinct digit.

AB × C.DE = AB + C.DE

What digit does each letter in this equation represent?

Well, given some combinatino of C.DE... we uniquely determine a number X (= AB) that satisfies the equation. I think...

So, if I weren't in a rush to get out of the house this morning... I'd write a quick a dirty program to cycle through the 720 or so combinations of C.DE and simply check to see where X is composed of 2 digits that aren't in the composition of C.DE.

Posted by SilverKnight on 2003-10-24 08:22:10