PPSC Excise and Taxation Inspector 2018 Question Paper

A: 20 Minutes

Solution:

Let us assume the total time is 1 hour.

- Without stoppages: Train covers 150 km in 1 hour.

- With stoppages: Train covers only 100 km in 1 hour (effective speed).

Let the train actually run for \( t \) hours at 150 km/h. 

Then, distance covered = \( 150t = 100 \) km

\[t = \frac{100}{150} = \frac{2}{3} \text{ hours}\]

Stopping time = \( 1 - \frac{2}{3} = \frac{1}{3} \) hours

 \[\frac{1}{3} \times 60 = \textbf{20 minutes}\]

Correct Answer: 20 Minutes ✅