The speed of a bullet train is 35% more than that of an electric train. If the electric train takes 3 h 45 min for a fixed distance, what will be the time taken by the bullet train to cover the same distance?

Correct option is A

Given:

Speed of the bullet train is 35% more than that of the electric train.

The electric train takes 3 hours 45 minutes to cover the distance.

Concept Used:
we can use the formula for time, which is inversely proportional to speed when the distance is constant:

​$$\text{Time} \propto \frac{1}{\text{Speed}}$$

Solution:​​

Let the time taken by the electric train be $$t_{\text{electric}}$$ and the time taken by the bullet train be $$t_{\text{bullet}}$$​. We know:

Speed of bullet train = 1.$$35 \times \text{Speed of electric train}$$​

Time taken by bullet train = $$\frac{\text{Time taken by electric train}}{1.35}$$​

First, convert 3 hours 45 minutes to hours:

​$$3 \text{hours} + 45 \, \text{minutes} = 3 + \frac{45}{60} = 3.75 \, \text{hours}$$​​

​$$t_{\text{bullet}} = \frac{3.75}{1.35} \approx 2.78 \, \text{hours}$$ = 2$$\frac 79$$ hours​