Ratio

A ratio is used to compare two quantities. The quantities should be in the same units.

Example

A farmer has 3 cats and 7 dogs.

Write down the ratio of cats to dogs and the ratio of dogs to cats.

Cats : Dogs = 3 : 7

Dogs : Cats = 7 : 3

Question

The same farmer also has 85 sheep and 15 cows.

Write down the ratio of cows to sheep in its simplest form.

cows : sheep = 15 : 85

15 and 85 are both divisible by 5

\frac{{15}}{5} = 3

\frac{{85}}{5} = 17

So 15 : 85 = 3 : 17