Question

the public library has volunteers shelve books after they have been returned. when Lisa arrives to volunteer, there are five nonfiction books for every 9 fiction books. if there are 117 fiction books to Shelve, how many nonfiction books need to be shelved?

Answer 1

There are 5 nonfiction books for every 9 fiction books. so we understand the the rate of nonfiction to fiction is: 5 : 9

We are asked to find how many nonfiction books are there if there are 117 fiction ones.

So we use the following proportion applying the rate we know of nonfiction/fiction:

5 / 9 = x /117

where we represented with "x" the number of nonfiction books we need to find.

We solve for that "x" by multiplying both sides by 117:

5 * 117 / 9 = x

then x = 65

Then, there are 65 nonfiction books to shelve.