Question

In making 1000 revolutions, a wheel covers 88 km. The diameter of the wheel is
(a) 14 m
(b) 24 m
(c) 28 m
(d) 40 m

Answer 1

(c) 28 m
Distance covered by the wheel in 1 revolution$=\left(\frac{88\times 1000}{1000}\right)\mathrm{m}$
= 88 m
We have:
Circumference of the wheel = 88 m
Now, let the diameter of the wheel be d m.
Thus, we have:

$$\begin{gathered} \mathrm{\pi }d=88 \\ \Rightarrow \frac{22}{7}\times d=88 \\ \Rightarrow d=\left(88\times \frac{7}{22}\right) \\ \Rightarrow d=28\mathrm{m} \end{gathered}$$