How many ways are there to put 5 balls in 3 boxes if the balls are not distinguishable but the boxes are?
k = balls n = boxes
5 identical balls into 3 distinguishable boxes (I'm assuming no restrictions.....a box may be empty )
No. of ways = C ( k + n - 1 , n -1) = C ( 5 + 3 -1 , 3 -1) = C ( 7, 2) = 21 ways
+102 
