Question

Shubham covers a distance at a speed of 50 km/h in 4 hours. How long will it take for him to cover the same distance if he travels at a speed of 80 km/h?

• A. 100 minutes
• B. 80 minutes
• C. 150 minutes
• D. 120 minutes

Answer 1

The correct option is C 150 minutes

Given, a certain distance is covered at a speed of 50 km/h in 4 hours.

We know that more is the speed for the same distance the lesser is the time taken to travel.

$So,\text{Speed}\left(x\right)\propto \frac{1}{\text{Time}\left(y\right)}forthesamedistance$
$\therefore \frac{x_1}{x_2}=\frac{y_2}{y_1}$

Given,
$x_1=50km/h$
$y_1=4hours$
$x_2=80km/h$
$\text{and}{y}_2=\text{time taken at 80 km/h}$

$\Rightarrow y_2=\frac{x_1\times y_1}{x_2}$
$\Rightarrow y_2=\frac{50\times 4}{80}=\frac{5}{2}\text{hours}$

$\frac{5}{2}\text{hours}=\frac{5}{2}\times 60=150\text{minutes}$