Question

The area of a square field is $1369m^2$. How much time will Rita take to run $7$ times around it at the rate of $3km/h$

Answer 1

Let $a$ be the edge of the square.

Area of square field $=a^2=1369m^2\left(\text{Given}\right)$

$\Rightarrow a=\sqrt{1369}=37m$

Therefore,

Perimeter of field $=4a=4\times 37=148m$

Distance Rita have to run $=7\times 148=1036m=1.036km$

As we know that,

$\text{Speed}=\frac{\text{Distance}}{\text{time}}$

$\Rightarrow \text{Time}=\frac{\text{Distance}}{\text{speed}}$

Speed of Rita $=3km/h$

Time taken by Rita to run $7$ times around the field $=\frac{1.036}{3}\text{hour}$

$=\frac{1.036}{3}\times 60\text{min}=20.72\text{min}$