Question

There are 30 people at a meeting, They each shake hands with everyone. How many

handshakes were there? Hint: Think "The number of combinations of 30 people at a
meeting giving handshakes to each other 2 at a time."

Answer 1

There were 435 handshakes.

Explanation:

If one gives to all others keep cancelling the one who has already given a handshake. So if the first one gives to the other 29 people, the others don't have to give handshake to him again as they have already shaked hands with him.

The process goes like this 29+28+27+26+25+24+23+22+21+20+19+18+17+16+15+14+13+12+11+10+9+8+7+6+5+4+3+2+1

After adding these the answer is 435.

Answer 2

60 both hand or 30 if only one hand

Explanation: