**Source: GMAT Prep**

The rear wheels of a car crossed a certain line 0.5 second after the front wheels crossed the same line. If the centers of the front and rear wheels are 20 feet apart and the car traveled in a straight line at a constant speed, which of the following gives the speed of the car in miles per hour? (5280 feet = 1 mile)

A. \(\left(\dfrac{20}{5280}\right)\left(\dfrac{60^2}{0.5}\right)\)

B. \(\left(\dfrac{20}{5280}\right)\left(\dfrac{60}{0.5}\right)\)

C. \(\left(\dfrac{20}{5280}\right)\left(\dfrac{0.5}{60^2}\right)\)

D. \(\dfrac{(20)(5280)}{(60^2)(0.5)}\)

E. \(\dfrac{(20)(5280)}{(60)(0.5)}\)

The OA is A