Ben is driving on the highway at y miles per hour. (One mile equals 5,280 feet.) Ben's tires have a circumference of x feet. Which of the following expressions gives the number of revolutions each wheel turns in one hour? Options
A) 5,280(x/y)  B) 5,280(y/x)  C) 5,280(xy)  D) 5,280/(xy)  E) (xy)/5,280
In one hour, at the rate of y miles per hour, Ben covers y miles, so 5,280y feet.   The number of revolutions = distance/circumference = 5,280y/x.   Answer: 5,280(y/x).
<result>B</result>
Ben is driving on the highway at y miles per hour. (One mile equals 5,280 feet.) Ben's tires have a circumference of x feet. Which of the following expressions gives the number of revolutions each wheel turns in one hour?