If a tire rotates at 400 revolutions per minute when the car is traveling 48km/h, what is the circumference of the tire?
Pick:  A) 7 meters  B) 9 meters  C) 8 meters  D) 2 meters  E) 3 meters

Rationale: "400 rev / minute = 400 * 60 rev / 60 minutes = 24,000 rev / hour 24,000 * c = 48,000 m : c is the circumference c = 2 meters correct answer d"
Answer: D