Question

If maya goes to office at a speed of 40km/hr she reaches 5 minutes late. If she travel at speed of 60km/hr she is 10mints early. What is the distance to office from her home

Answer 1

Answer-

The distance between her office and home is 3 km.

Solution-

Let the distance between the office an her home is x km.

If she goes to office at a speed of 40 km/hr she reaches 5 minutes late

Let the time taken by her is t hours, so  

$\Rightarrow Speed=\dfrac{Distance}{Time}$

$\Rightarrow Time=\dfrac{Distance}{Speed}$

Putting the values,

$\Rightarrow t=\dfrac{x}{40}$

If she goes to office at a speed of 60 km/hr she reaches 10 minutes early

Let the time taken by her is t' hours, so  

$\Rightarrow Speed=\dfrac{Distance}{Time}$

$\Rightarrow Time=\dfrac{Distance}{Speed}$

Putting the values,

$\Rightarrow t'=\dfrac{x}{60}$

According to the question, the time difference between the timings are 15 minutes

$\Rightarrow t-t'=\dfrac{15}{60}$

$\Rightarrow \dfrac{x}{40}-\dfrac{x}{60}=\dfrac{1}{4}$

$\Rightarrow \dfrac{30x-20x}{120}=\dfrac{1}{4}$

$\Rightarrow \dfrac{10x}{120}=\dfrac{1}{4}$

$\Rightarrow x=\dfrac{120}{4\times 10}$

$\Rightarrow x=\dfrac{120}{40}$

$\Rightarrow x=3$

Therefore, the distance between her office and home is 3 km