Question

Here are 10 people in a room. If each person shakes hands with exactly 3 other people, what is the total number of handshakes?

Answer 1

hey the answer is 6 .........

Answer 2

The total number of pairs that can be formed from 10 people = 10C2 = 45.

If all of these pairs shake hands, each person in the room will shake hands with EVERY OTHER PERSON in the room.

The result will be 9 HANDSHAKES PER PERSON.

Since we want only 3 HANDSHAKES PER PERSON, we must divide by 3:

45/3 = 15.