In how many ways can 2 books be chosen from 6 different books?

Answer and explanation

Correct answer: D. 15

  1. Step 1: Order does not matter, so .
Answer
15.
Why not the others: 30, 12 and 21 don't fit.

Practise more Calculus, functions and statistics.

Free questions with an explanation for every one, and full timed NSW HSC mock tests.