So if the ratio of red to blue is 8:3 and there are 15 blue cars then there are 40 red cars.
If the ratio of red to white is 2:10 then then there are 200 white cars.
Step-by-step explanation:
15 divided by 3 is 5. So you multiply 8 by 5 to get 40. 40:15 reduces to 8:3.
With 40 red cars the ratio of 2:10 would be made into 40:200.
The fractions/ratios have to remain proportional.