Navjivan Express from Ahmedabad to Chennai leaves Ahmedabad at 6:30 am and travels at 50kmph towards Baroda situated 100 km away. At 7.00 am Howrah-Ahmedabad Express leaves Baroda towards Ahmedabad and travels at 40 kmph. At 7:30 am Mr. Shah, the traffic controller at Baroda realizes that both trains are running on the same track. How much time does he have to avert a head-on collision between the two trains?
Navjivan Express from Ahmedabad to Chennai leaves Ahmedabad at 6:30 am and travels at 50kmph towards Baroda situated 100 km away. At 7.00 am Howrah-Ahmedabad Express leaves Baroda towards Ahmedabad and travels at 40 kmph. At 7:30 am Mr. Shah, the traffic controller at Baroda realizes that both trains are running on the same track. How much time does he have to avert a head-on collision between the two trains? Correct Answer 15 min
Given:
Navjivan Express from Ahmedabad to Chennai leaves Ahmedabad at 6:30 am and travels at 50km/h towards Baroda
At 7.00 am Howrah-Ahmedabad Express leaves Baroda towards Ahmedabad and travels at 40 km/h
At 7:30 am Mr. Shah, the traffic controller at Baroda realizes that both trains are running on the same track
The distance between Ahmedabad to Baroda is 100 km.
Concept:
Time = Distance/Speed
Calculation:
At 7.30 AM, Distance travel by Navijan express is
⇒ 50 × 1
⇒ 50 km
At 7.30 AM, Distance travel by Howrah-Ahmedabad Express is
⇒ 40 × 1/2
⇒ 20 km
Now, Distance left between the both train is
⇒ 100 - 50 - 20
⇒ 30 km
Both train travel in opposite direction, then relative speed of the trains is
⇒ 50 + 40
⇒ 90 km/h
Time taken to cover this distance by both train is
⇒ 30/90
⇒ 1/3 hour = 20 min
So, He have to time less than 20 min to avert the head on collision between two trains.
∴ 15 min