Question

A wheel has diameters 84 km. Find how many complete revolution must it take to cover 792 meters

Answer 1

Let r be the radius of the wheel , Then,
Diameter $=84cm$
$\Rightarrow$ $2r=84cm$
$\Rightarrow$ $r=42cm$
$\therefore$ Circumference of the wheel $=$ $2\pi r=2\times \frac{22}{7}\times 42cm$ $=264cm=2.64m$

So, the wheel covers $2.64$ meters in one complete revolution.

$\therefore$ Total number of revolutions in covering $792$ meters $=$ $\frac{792}{2.64}$ $=300.$

Hence, the wheel takes $300$ revolutions in covering $792$ meters.