Question

A man has 7 friends. In how many ways he can invite one or more of them for a tea party

• A. 128
• B. 256
• C. 127
• D. 130

Answer 1

The correct option is C

127

Required number of ways = $2^7-1$ =127

{Since the case that no friand be invited i.e., ${}^7{C}_0$is excluded}