You have to answer 2 questions for the exam. There are 7 essays to choose from. How many different groups of 2 essays could you possibly choose?

Question

Mathematics

Jabari Fry

4 May, 01:51

You have to answer 2 questions for the exam. There are 7 essays to choose from. How many different groups of 2 essays could you possibly choose?

+4

Answers (1)

Know the Answer?

Korbin Strickland · Answer 1

21

Step-by-step explanation:

Since the order of the essays isn't important, the number of ways you can choose 2 from 7 is:

₇C₂ = 7! / (2! (7-2) !)

₇C₂ = 7! / (2! 5!)

₇C₂ = 7*6*5! / (2*1 * 5!)

₇C₂ = 7*6 / 2

₇C₂ = 21