Question

Blake has entered a mountain bike competition at Starvation Flats Bike Park. Placement in the competition is determined by a person's average speed over four laps around the course. The course itself is of a mile long. If Blake completed the four laps in 12 minutes, then his average speed around the track is
miles per hour.

Answer 1

distance = rate * time, or rewritten rate = distance / time ---> r = d/t 
4 laps, 1 mile per lap = 4 miles = d 
12 minutes = 1/5 of hour (12 min/60 min = 1/5) = t 

r = 4/(1/5) mph