Posted by Jarrod on .
If a tire rotates at 150 revs/min when the truck is travelling 40km/h, what is the circumference of the tire?
4.44 meters

Math 
Steve,
40km/hr = 40/60 km/min = 40000/60 m/min
40000/60m/min / 150rev/min = 40000/9000 m/rev = 40/9 m/rev = 4.44 m/rev