8448 is a multiple of 44. Change the two 4s for different odd numbers X and Y, so 8XY8 can be divided by XY. No computers allowed!
It's given that 8XY8 is divisible by XY, and so subtracting XY0 gives 8008, which is divisible by 8 times 7 times 11 times 13. 13 is the only factor that is odd with two different digits, XY must be 13 and 8138 is divisible by 13.
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Posted by Gamer
on 2004-07-20 12:59:37 |