There are 15 students in a social studies class. Two students will be selected to present their term projects today. In how many different orders can two students be selected?

Question

Mathematics

Kathy Mendez

18 October, 16:48

There are 15 students in a social studies class. Two students will be selected to present their term projects today. In how many different orders can two students be selected?

+4

Answers (1)

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Alvin Garcia · Answer 1

Given:

15 students

2 students must be chosen.

No repetition, no order

This is a combinations problem. We use this formula: n! / (n-r) ! (r!)

n = 15; r = 2

15! / (15-2) ! (r!) ⇒ 15! / 13! * 2! = 105