1. The digits 0, 2, 4, 6 and 8 are to be placed, one in each box, in the multiplication
problem shown, so that the product is as large as possible. What is the product?
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x [ ][ ]
Solution
The 1s digit has the least influence in the numerator, so it is 0.
Then, we want the leading digits to be 8 and 6. Then, the 4 multiplied by 8 and 2 by 6 will get a
bigger result than multiplying 4 by 6 and 2 by 8.
Thus, we either have 640 * 82 or 820*64.
In both cases, the result is 52480
Note that we could simply try all 5! results and verify that this is the result.