The radius of the wheel of a bus is 35 cms and the speed of the bus is 66 km/h, then the r.p.m. (revolutions per minutes)of the wheel is	Choose the correct option.
A) 200
B) 250
C) 300
D) 500
E) None of these
Radius of the wheel of bus = 35 cm. Then,   circumference of wheel = 2Ï€r = 70Ï€ = 220 cm   500istance covered by bus in 1 minute   = 66â„60 Ã— 1000 Ã— 100 cms   500istance covered by one revolution of wheel   = circumference of wheel   = 220 cm   âˆ´ Revolutions per minute = 6600000/60Ã—220 = 500   Answer 500
<result>D</result>
The radius of the wheel of a bus is 35 cms and the speed of the bus is 66 km/h, then the r.p.m. (revolutions per minutes)of the wheel is