Correct option is C
Given:
Trains are to run daily from both Chennai and New Delhi
Departure time from each end: 6:00 PM daily
Travel time for each train: 36 hours (i.e., 1.5 days)
Solution:
To run a daily train service in both directions, we need enough rakes to account for:
Trains that are in transit (since 36 hours is more than a day)
Trains that are ready to depart
Trains that may still be returning or being prepared
Let’s analyze this with a simple schedule-based logic:
Day 1: One train departs from Chennai and one from New Delhi at 6:00 PM
These trains will reach the destination at 6:00 AM on Day 3
Day 2: Again, trains depart at 6:00 PM from both stations
The previous rakes are still in transit, so we need 2 more rakes
On Day 3, the first set of trains arrive at 6:00 AM
But we already need trains ready for 6:00 PM on Day 3 as well
So at any point, we have:
Two trains on their way (from Day 2's dispatch)
Two more leaving today (Day 3)
Hence, at least 4 rakes are needed to ensure a train is available for daily dispatch from each side.
Final Answer:
S. Ans. (C) 4
