Q.

The number of ways, in which 16 oranges can be distributed to four children such that each child gets at least one orange, is  [2026]

1 403  
2 429  
3 455  
4 384  

Ans.

(3)

Let oranges be identical, then

x1+x2+x3+x4=16,  and x1,x2,x3,x41

or x1'+x2'+x3'+x4'=12

so total number of solutions are

=C312+3=C315=455