Question

a man has 6 friends. In how many ways may he invite one or more of them at dinner ?​

Answer 1

Answer:

to call them he will go to there home for calling

Answer 2

He has 6 friends and he wants to invite one or more. That is the same as saying he wants to invite at least 1 of his friends.

So, the number of ways he could do this is:

• Invite only one friend

• Invite any two friends

• Invite any three friends

• Invite any four friends

• Invite any five friends

• Invite all six friends

This can be thought of in terms of combinations. Inviting $r$  friends out of $n$  is same as choosing $r$  friends out of $n$

So, we can write the possibilities as:

=6C1+6C2+6C3+6C4+6C5+6C6

=6+15+20+15+6+1

=63=63

Therefore, there are 63 ways in which he can invite 1 or more friends out of his 6 friends.