The number of ways of distributing 8 identical balls in 3 distinct boxes so that none of the boxes is empty is
- (A)5
- (B)
- (C)
- (D)21✓ Correct
Answer: (D)
Solution
The requirement that no box stays empty is handled neatly by first dropping one ball into each of the three boxes; that leaves identical balls to spread freely among the boxes. The number of ways of doing this is the stars-and-bars count .
JEE Main · 2004 · 24 Apr 2004 · Offline · Single correct option