How many people?

[cancel2 2022]

[h=1]If there are 66 handshakes between people at a party, how many people are in the room? Try to work it out without looking it up![/h]

 

[Althea]

Can't get to 66? If there are 9 people in the room, there would be 72. If there are 8 people in the room, there would be 56.

 

[MAGA MAN]

I just worked it out by putting circles of dots on the paper, starting with 6, up to 8 until I figured out the formula. It's 1+2+3+4+5+6+7+8+9+10+11=66, so the answer is one more than the last number added which is 12 people.