Can anyone help get me started on this?
Provide a combinatorial argument to show that if n and k are positive integers with n = 3k, then n!/(3!)^k is an integer.
The second step states to "generalize" the result of the above.
So if we have items, which can be sorted into groups of , each group containing identical items, then the number of arrangements of the items is . This number is therefore an integer.
To generalise this, the same argument applies if , for any positive integer , whereby is therefore also an integer.