The picture shows how many cans of blue and yellow paint make the green shade. Ravi has 8 cans of blue paint. How many cans of yellow paint does he need for the same shade?

The ratio 2 : 3 says: for every 2 of one thing, there are 3 of another. In a fruit basket of 2 apples and 3 oranges, the ratio of apples to oranges is 2 : 3. **Order matters** — the ratio of oranges to apples in the same basket is 3 : 2. The two quantities must be in the same unit (you can't ratio apples to kilograms unless you convert).