Question

A person goes in for an examination in which there are four papers with maximum of m marks from each paper.the number of ways in which one can get 2m marks is ?

Answer 1

`=^{2m+3}C_3`

Explanation:

The number of ways in which one can get `N=2m` marks out of `R=4` papers (including the cases of getting zero mark in some papers)

`=^{N+R-1}C_{R-1}`

`=^{2m+4-1}C_{4-1}`

`=^{2m+3}C_3`