There are 10 people in a room. If each person shakes hands with exactly 3 other people, what is the total number of handshakes? Choose the correct choice from the following answers
A) 15	B) 30	C) 45	D) 60	E) 120
4 people: shrive 555, cranky, karishma and Mr X   We have to shake hands in this group such that each person shakes hands with 3 people.   So shrive555 starts:   shrive555 - craky : 1 handshake but 2 hands were shaken. shrive 555's and cranky's   shrive 555 - karishma : 1 handshake but 2 hands were shaken. shrive 555's and karishma's   shrive 555 - Mr X : 1 handshake but 2 hands were shaken. shrive 555's and Mr X's   Now shrive 555 has shaken hands with 3 people. There were 3 handshakes. But 6 hands were shaken.   Now, when all 4 of us shake hands with 3 people, each person's hand will be shaken 3 times. i.e. in all 12 hands will be shaken. But they will add up to only 6 handshakes.   The other 3 handshakes will be:   cranky - karishma   cranky - Mr X   karishma - Mr X   So all of us have shaken hands with exactly 3 people.   Similarly when there are 10 people, each person shakes his hand 3 times. So in all 30. But 2 of these hands combined to make one handshake. So we will get only 15 total handshakes.   15NSWER:15
<result>A</result>
There are 10 people in a room. If each person shakes hands with exactly 3 other people, what is the total number of handshakes?