Question

If n balls are distributed into m boxes, so that each ball is equally likely to fall in any box, the probability that a specified box will contain r balls is

Answer 1

Correct option (c)

Explanation:

The total number of ways of distributing n balls into m boxes is mn which are assumed to be equally likely. 

Since r balls which should go to the specified box can be chosen in ⁿC_r ways and for any such way the remaining (n – r) balls can be distributed to the

[where A is the event that a specified box will contain r balls]