Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
The diameter of the driving wheel of a bus is 140 cm. How many revolutions per minute must the wheel make in order to keep a speed of 66 kmph? 66 × 1000
Answer
Answer (as printed):
Explanation
Distance to be covered in $1 \mathrm{min} .=\left(\frac{66 \times 1000}{60}\right) \mathrm{m}=1100 \mathrm{m}$. $$\begin{aligned} & \text { Circumference of the wheel }=\left(2 \times \frac{22}{7} \times 0.70\right) \mathrm{m}=4.4 \mathrm{m} . \\ & \therefore \text { Number of revolutions per min. }=\left(\frac{1100}{4.4}\right)=250 . \end{aligned}$$