Question

No of ways of taking identical 3 balls from 12 identical ablls

Answer 1

Therefore, E(j=3) = 11!/(2!)(9!) = 55 = number of ways 12 identical balls can be distributed to 3 boxes such that each gets at least 1 ball and the maximum to any box is 10 balls. Those 3-box group combinations which include 3 balls in a box are: 3,8,1; 3,7,2; 3,6,3; 3,5,4.