Question

The ratio of red cars to blue cars in a parking lot was 5 : 3. If there were 40 red cars how many blue cars were there?

Answer 1

Every 5 red cars there are 3 blue cars
so if there are 40 red cars there are going to be  24 blue cars

Answer 2

If there are 40 red cars, there would be 24 blue cars because, you represent the equation as 5 : 3
                        40 : ?
You do 40 divided by 5 which is 8. You then multiply 3 x 8 which is 24. 
24 blue cars :)