#### mixtapevanity

##### New member

- Joined
- Apr 13, 2008

- Messages
- 1

Originally I thought of it as 18 choose 3, where order doesn't matter, so then we have 15 remaining. So we do 15 choose 3, divide it by 3! since order doesn't matter and continue until we are at 3 student left, which means only one choice. Then multiply those numbers together and I get something like 1.37225088 * 10^11.

Is this correct?