Two dogsled teams raced across a 500-mile course in Alaska. Team A finished the course in 5 fewer hours than team B. If team A’s average speed was 5 miles per hour greater than that of team B, what was team B’s average speed, in miles per hour?
Pick one:
A) 12	B) 15	C) 18	D) 20	E) 25
Let v be team B's average speed.   Time = Distance/Rate and the time difference was 5 hours.   500/v - 500/(v+5)= 5   500v + 2500 - 500v = 5(v)(v+5)   500 = (v)(v+5)   (20)(25) = (v)(v+5)   v = 20 mph   The answer is 20.
<result>D</result>
Two dogsled teams raced across a 500-mile course in Alaska. Team A finished the course in 5 fewer hours than team B. If team A’s average speed was 5 miles per hour greater than that of team B, what was team B’s average speed, in miles per hour?