Question

Sunil has 6 friends. In how many ways can he invite two or more of his friend for dinner?

Answer 1

He can invite two or more friends by inviting in following possible ways
2 friends can be selected out of 6 in 6C2 = 15 ways
3 friends can be selected out of 6 in 6C3 = 20 ways
4 friends can be selected out of 6 in 6C4 = 15 ways
5 friends can be selected out of 6 in 6C5 = 6 ways
6 friends can be selected out of 6 in 6C6 = 1 ways
Therefore the required number of ways (combinations) = 15 + 20 + 15 + 6 + 1 = 57

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