When Carla looked at the library, she noticed that for every 2 nonfiction books, there were 5 fiction books. If there are 161 books total, how many of them are not nonfiction books.

138 nonfiction

Step-by-step explanation:

Ratio problem, we are going to use the part to all approach

Step one:

given data

the ratio of nonfiction to fiction books is 2 to 5

otherwise expressed as 2:5

the total ratio is 2+5= 7

the total number of books is 161,

applying the part to all approach

nonfiction to all is

let the nonfiction be x

2/7=x/161

cross multiply we have

7x= 161*6

7x=966

divide both sides by 7

x=966/7

x=138 nonfiction

138 nonfiction