The diameter of each wheel of car is 70 cm. If each wheel rotates 400 times per minutes, then the speed of the car (in km/hr) if : ( Take = 227 )

Answer: Option C

Circumference of wheel = 2πr
⇒ 2πr
⇒ 2 × $$\frac{22}{7}$$ × $$\frac{70}{2}$$
⇒ 220 cm
Speed per hours :
= $$\frac{220\times 400\times 60}{1000\times 100}$$
= 52.8 km/hr