The diameter of the driving wheel of a bus in 140 cm. How many revolutions per minute must the wheel make in order to keep a speed of 20 kmph?  Choose the correct option:
A) 21.21  B) 20.25  C) 32.25  D) 75.75  E) 62.61
distance covered in 1 min=(20*1000)/60=333.33m   circumference of the wheel=(2*(22/7)*.70)= 
<gadget id="calculator">(2*(22/7)*.70)</gadget>
<output>4.4</output>
4.4m   no of revolution per min=333.33/4.4=75.75   ANSWER:75.75
<result>D</result>
The diameter of the driving wheel of a bus in 140 cm. How many revolutions per minute must the wheel make in order to keep a speed of 20 kmph?