Question

Manisha cycles to her school at an average speed of 15 km/hr and takes 30 minutes to reach her school. If she wants to reach her school in 15 minutes, then what should be her average speed?

Answer 1

Higher is the speed, lesser will be the time taken to cover the same distance.
Hence, it is a case of inverse proportion.

$\begin{array}{ccc}Speedofcar\left(km/hr\right)& 15& X\\ Timetaken\left(mins\right)& 30& 15\end{array}$

$\Rightarrow \frac{15}{30}=\frac{15}{x}$

$\Rightarrow x=30km/hr$