Question

The number of wrecks at a certain intersection varies directly as the number of cars that travel through the intersection. If there are 31 wrecks when 1,085 cars have traveled through the intersection, how many cars have passed through the intersection after 7 wrecks?

Answer 1

Explanation:

Comment

This can be done as a proportion. A proportion is 2 equal ratios. If you know three parts of the proportion then you can solve for the 4th.

Proportion

31 wrecks/1085 cars = 7 wrecks / x cars

Solution

31 wrecks/1085 cars = 7 wrecks / x cars Cross Multiply

31 * x = 1085 * 7 Simplify the right

31 * x = 7595 Divide both sides by 31

31 * x/31 = 7595/31

x = 245

Answer 7 wrecks means 245 cars have passed the intersection