A	B	C
D		E
F	G	H

The letters A-H are different digits from 1 to 9.

Read from left to right and top down, the four numbers formed are primes.

There is not just one solution. (Flipping along the diagonal A-H does not present a different solution).

Suppose "0" is allowed, and A cannot have that value, what other unique solutions are available?

(In reply to re: Extensive === a powerful tool by pcbouhid)

Interesting looking site,  I could well have used that tool when considering this problem instead of setting up an spreadsheet which required me to enter values manually; site is worth bookmarking. Thanks Paulo.

Posted by brianjn on 2009-07-11 21:44:26