THE RATIO OF BUSES TO CARS CAN BE EXPRESSED AS 2X

1. The ratio of buses to cars can be expressed as 2x: 23x. We can

write an equation that represents the fact that there are 630 fewer

buses than cars: 2x + 630 = 23x.

Solving this equation for x yields the following:

2x + 630 = 23x

630 = 21x

30 = x.

There are 23x cars on River Road which equals 23 × 30 = 690 cars.

The correct answer is D.