A train is going from station A to B. In the journey, train stopped at station C for 20 minutes, at Station D for 25 minutes and at station E for 30 minutes. If the speed of train is 80 km/hr. Find the distance between A and B if the total time taken to complete the whole journey is 90 minutes.?

Option 3 : 20 km

Given:

Speed of the train = 80 km/hr

Train stopped at 3 stations for 20 minutes, 25 minutes and 30 minutes respectively

Total time taken to complete the journey = 3/2 hours

Formula used:

Time = Distance/Speed

Calculation:

Let the distance between Station A and B be x km

Average speed of the whole journey = 80 km/hr

Time taken to cover x km only beside stopping at stations = x/80 hr

Total time taken to complete the whole journey = 90 minutes

Total time taken to complete the whole journey = 90/60 hr

⇒ 3/2 hours

Total time taken at three small stations C, D and E = 75 minutes

Total time taken at stations C, D and E = 75/60 hr

⇒ 5/4 hour

Now, Total time taken to complete whole journey = x/80 + 5/4 hour

Total time given = 3/2 hours

Now, x/80 + 5/4 = 3/2

⇒ x/80 = 3/2 – 5/4

⇒ x/80 = 1/4