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? 462 44 11 231

Answer 1

22! / 20! × 2!

`21 * 11 = 231 \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\`