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?

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

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 :)

25% increaseplus i think decrease i only know increase: ((