Question

There are 22 students in mario's class. mario's teacher is planning to pair the students up for a project. how many different combinations of pairs are possible? 11

Answer 1

231

Explanation:

Answer 2

231. I did this manually by pairing up all the combinations. Student #1 would have 21 people to pair up with. Then, Student#2 would now only have 20 students to pair with ( student#1 already paired with student#2) and so it goes from 21 to 1 to get 231