There are three ways to write 10 as the sum of four odd positive integers, assuming that order does not matter. They are 1+1+1+7, 1+1+3+5, and 1+3+3+3. In how many ways can 20 be written as the sum of eight odd positive integers?
Source: The Moscow Puzzles, by Boris Kordemsky.
[Mailbag] What Do You Do with the Ideas You Used to Call “Mistakes” - Guillaume Paré, in the very interesting comments of my last post where I urged us to reconsider mistakes: I do agree with what is written, but I am still w...
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