Question

The diameter of a wheel is 84 cm. How many revolutions will it make to cover 792 m?
(a) 200
(b) 250
(c) 300
(d) 350

Answer 1

(c) 300

Let d cm be the diameter of the wheel.
We know:
Circumference of the wheel$=\mathrm{\pi }\times d$
$$\begin{gathered} =\left(\frac{22}{7}\times 84\right)\mathrm{cm} \\ =264\mathrm{cm} \end{gathered}$$

Now,
Number of revolutions to cover 792 m$=\left(\frac{792\times 1000}{264}\right)$
=300