A voter can give vote to either 1 candidate or 2 candidates or 3 candidates or 4 candidates. Case 1 : When he give vote to only 1 candidate then no ways =10C1 Case 2 : When he give vote to 2 candidates then no ways =10C2 Case 3 : When he give vote to 3 candidates then no ways =10C3 Case 4 : When he give vote to 4 candidates then no ways =10C4 So, total no of ways he can give votes =10C1+10C2+10C3+10C4 =385 Note : Here we use addition rule as he can vote any one of those four rules. Whenever there is "or" choices, we use addition rule.