Question

A distance of $14.4km$ covered in $2$ hours $40$ minutes. Find the speed in $m{s}^{-1}$. With this speed, Sakshi goes to her school, $240m$ away from her house and then returns back. How much time, in all, will Sakshi take?

Answer 1

Distance $=14.4km$

Time taken to cover $=2hrs40mins$

$=2.\frac{2}{3}$

$=\frac{8}{3}hrs$

$\Rightarrow$ Speed in m/s $=\frac{14.4\times 1000}{\frac{8}{3}\times 3600\times 10}=\frac{3}{2}m{s}^{-1}$

$\Rightarrow$ Distance from house to school and bank $=(240+240)m=480m$

$\Rightarrow$ Time taken $=\frac{480}{1.5}$ second $=320$ seconds

$=\left(\frac{320}{60}\right)min$

$=50min20sec.$

Hence, the answer is $50min20sec.$