Question

A man has 6 friends. In how many ways can he invite one or more of his friends at
a dinner?
There are 8 true-false statements in a question paper. ​

Answer 1

Answer:

Specify the no. of people he need to invite at a time...

Answer 2

Answer:

in more ways her can ......

He can invite one or more friends by inviting 1 friend, or 2 friends or 3 friends, or all the 6 friends.

1 friend can be selected out of 6 in 6C1 = 6 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) = 6 + 15 + 20 + 15 + 6 + 1 = 63