Question

Christine drives her car 144 miles and has an average of a certain speed. If the average speed has been 5 mph more, she could have traveled 168 miles in the same length of time. What was her average speed?

Answer 1

Let's make a system of equations:

144/x=y

168/(x+5)=y

So,

144/x=168/(x+5)

Solving using cross multiplication,

x=30

So, her average speed for driving 144 miles was 30 miles per hour.

-Hunter