What's the pair of numbers made using 1-9 which has maximum product?

Asked Dec 24 '13 at 16:33

Active Dec 24 '13 at 16:51

Viewed 45 times

The task is to find a pair of numbers whose digits are 1-9, no digit repeated such that their product is maximum possible.

eg. 123 and 456789 is one such pair.

Question: Please suggest a way to do it.

I tried writing a code in Python but failed. Any logical approach is appreciated.

edited Dec 24 '13 at 16:51

Gerry Myerson

asked Dec 24 '13 at 16:33

Cheeku

Isn't this a Project Euler problem? I feel like I've seen something about pandigital products. – apnorton Dec 24 '13 at 16:42
A starting point for this problem, if I were to write a search program: If we plot $z=xy$, we find that the curve is highest in the first octant when $x \approx y$, and $x$ and $y$ are large. Thus, I would look for the largest two numbers I could make with the smallest difference. – apnorton Dec 24 '13 at 16:51

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