Brian, Zack, Dan,Jay, Ed, and Andrew want to play a two-player video game. If only two people can pay at a time, how many different pairs can they form for the first matchup?
A 12
B 36
C 15
D 30
Brian x Zack Brain x Dan Brian x Jay Brian x Ed Brian x Andrew Zack x Dan Zack x Jay Zack x Ed Zack x Andrew Dan x Jay Dan x Ed Dan x Andrew Jay x Ed Jay x Andrew Ed x Andrew
Those are all the possibilities. There are 15, so C would be the correct answer.
