Question

How long will a boy take to run around a square field of side $35\text{m}$, if he runs at the rate of $9\text{km/hr}$?

Answer 1

Perimeter$=$distance run $=4\times 35$

$=140\text{m}$

Time $=\frac{\text{distance}}{\text{speed}}$

$⟹$ Speed$=\frac{9\text{km}}{1\text{hr}}=\frac{9000\text{m}}{60\text{min}}$

$⟹$ Time $=\frac{140}{\frac{9000}{60}}$

$⟹$ Time $=\frac{140\times 60}{9000}$ Minutes

$⟹$ Time $=\frac{84}{90}=\frac{14}{15}$ Minutes