The distance between two stations A and B is 107 km. A 1.8 km long train starts from station A for station B at a speed of 90 km/h. After 10 minutes, another train, 1.2 km long, starts from station B and runs towards station A at a speed of 100 km/h. What is the distance of the point from station A where the two trains pass each other?
The distance between two stations A and B is 107 km. A 1.8 km long train starts from station A for station B at a speed of 90 km/h. After 10 minutes, another train, 1.2 km long, starts from station B and runs towards station A at a speed of 100 km/h. What is the distance of the point from station A where the two trains pass each other? Correct Answer 58.2 km
Given:
Distance between two stations is 107km.
Length and Speed of first train is 1.8km and 90km/hr respectively.
Length and Speed of another train is 1.2km and 100km/hr respectively.
Formula Used:
Speed = Distance/Time,
Relative speed when running opposite = Distance/Sum of the speed of both the trains
Calculation:
First train ran for 10 minutes,
In 10 minutes, train will cover,
⇒ 90 × 10/60
⇒ 15 km
Actual distance to cover now,
⇒ 107 – 92
⇒ 92 km
Now both trains are running in opposite direction,
⇒ Relative speed = 100 + 90
⇒ Ralative speed = 190 km/hr
Time required to cross = Distance to cover/Relative speed
⇒ Time taken = 95/190
⇒ Time taken = 1/2 hr
In 1/2 hr first train will cover,
⇒ 1/2 × 90
⇒ 45km
So the total distance covered by first train till now is,
⇒ 15 + 45
⇒ 60 km.
Actual distance covered i.e. end point of a train will at,
⇒ Distance covered – length of a first train
⇒ 60 – 1.8
⇒ 58.2km
∴ Total distance covered from point A is 58.2 km.