A bus trip of 660 miles would have taken 1 hour less if the average speed V for the trip had been greater by 5 miles per hour. What was the average speed V, in miles per hour, for the trip?
Choose the correct choice.
A) 40	B) 45	C) 50	D) 55	E) 60
The time is the distance/speed. The time difference is 1 hour.   660/V - 660/(V+5) = 1   660(V+5) - 660V = (V)(V+5)   3300 = (V)(V+5)   55*60 = (V)(V+5)   V = 55 mph   The answer is 55.
<result>D</result>
A bus trip of 660 miles would have taken 1 hour less if the average speed V for the trip had been greater by 5 miles per hour. What was the average speed V, in miles per hour, for the trip?