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  Select the correct option.
A) 200  B) 250  C) 300  D) 500  E) none of these

Rationale: radius of the wheel of bus = 35 cm . then , circumference of wheel = 2 ï € r = 70 ï € = 220 cm distance covered by bus in 1 minute = 66 â  „ 60 ã — 1000 ã — 100 cms distance covered by one revolution of wheel = circumference of wheel = 220 cm â ˆ ´ revolutions per minute = 6600000 / 60 ã — 220 = 500 answer d
Answer: D