SOLUTION: There are 6 positions on a flagstaff and 6 flags, of which 3 are red, 2 blue, and 1 white. How many different signals can be made by displaying all the flags simultaneously?
If all 6 flags were distinguishable the answer would be 6!
However, since flags of the same color are not distinguishable, we must
divide that by the each of the numbers of ways to arrange the
indistinguishable flags. So the solution is
Edwin