Given three cubes with integer edge lengths, if the sum of their surface areas is , then the sum of their volumes is ( ).
Solution
Denote the edge lengths of the three cubes as , and , respectively. Then we have
i.e. . We may assume that
Then
It follows that . So , and this means that can only be , , or .
If , then
It is easy to see that , . So we get the solution .
If , then
This means that and ; it follows that or , so or ; in both cases has no integer solution.
If , then
It is easy to see that , is the only solution.
If , then
So , or . This means that , but , so . Then and cannot be an integer.
In summary, there are two solutions: and . Then the possible volumes are
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