How many ways are there to put 6 balls in 3 boxes if the balls are distinguishable but the boxes are not?
Hint(s):
The following cases are the most likely to be miscounted:
* Putting 2 balls into each box.
* Putting 3 balls into two boxes.
* Putting 4 balls into a box and 1 ball into the other 2 boxes.
The answer is not 207.