Vanessa is packing her bags for her vacation. She has 6 unique books, but only 3 fit in her bag. How many different groups of 3 books can she take?

Mathematics · Middle School · Tue Nov 03 2020

Answered on

Given :

Vanessa has 6 unique books but only 3 can fit in

Formula:

For selecting “r” items from “n” items

nCr = n!/r!(n-r)!

n = 6 and r = 3

6C3 = 6!/3!(6-3)!

= 6 × 5× 4 × 3!/3×2 × 3!

= 5 × 4

= 20

 

Hence, 20 different group of 3 books she can take .