Posted by **Madi** on Monday, October 25, 2010 at 11:23pm.

How many people were at a party if There were 105 handshakes at a party and if each person at the party shook hands with exactly once with every other person. The answer is 15. How do I write the problem?

- math -
**makhan pal**, Monday, September 26, 2016 at 12:27pm
n(n-1)/2=105, > n^2-n-210=0, n^2-15n+14n-210=0, > n(n-15)+14(n-15)=0, >(n-15)(n+14)=0, so, n=15, =-14 , as -ve is not possible, so n=15, ans will be 15 men

## Answer This Question

## Related Questions

- math - At a party, there were 105 handshakes. If each person shook hands exactly...
- 7th grade - At a party, there were 105 handshakes. If each person shook hands ...
- math - taylor was having a party.she invited 20 friends to her party, if each ...
- math - At a party everyone shook hands with everyone exactly once there were a ...
- Algebra - A scientist wants to research the potential spread of germs by contact...
- Math - At a party, 55 handshakes took place as everyone shook hands with ...
- Math - At a party, 55 handshakes took place as everyone shook hands with ...
- Math1 - An undisclosed number of friends gather for dinner. Each person shakes ...
- Math(Please Help!) - An undisclosed number of friends gather for dinner. Each ...
- math - At the medal presentation, each person shook hands with every other ...

More Related Questions