Kai buys 6 fiction books and 4 nonfiction books. what is the ratio of fiction books to nonfiction books? a 3 : 10 b 2 : 10 c 2 : 3 d 3 : 2

6 fiction books to 4 nonfiction books is a ratio of 6:4.
This ratio needs to be simplified, and simplifying a ratio is done in the same way as simplifying a fraction. We find the greatest common factor (GCF) of 6 and 4. The GCF of 6 and 4 is 2, because 2 is the largest number that fits into both 6 and 4.
When you divide each side of a ratio by a factor of both numbers, the simplified ratio stays proportional to the unsimplified ratio. (We're using the biggest factor of 6 and 4, which is 2.)
6 divided by 2 is 3, and 4 divided by 2 is 2.

Your simplified ratio is 3:2 (answer D).