A and B are two stations 455 km apart. A train starts from station A at 9 am and runs towards station B with a speed of 55 kmph. Another train starts from station B at 10 am and runs towards station A with a speed of 45 kmph. At what time do the trains meet?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 2 pm
The first train runs alone for one hour; after that, the trains move towards each other, so the gap closes at the sum of their speeds.
From 9 am to 10 am the first train covers 55 km, so the gap at 10 am is \(455-55=400\) km
From 10 am the gap closes at \(55+45=100\) km per hour
Time to meet \(=400\div100=4\) hours after 10 am, that is, at 2 pm