Aptitude :: Problems on Trains

Practice :: Problems on Trains - General Questions
Problems on Trains - General Questions

Page Title 6. At a speed of 120 km/h a train is running. The length of the train is 150 meters. How long it will take to cross a platform 100 m long?
20 Seconds
8 Seconds
7.5 seconds
9 Seconds
Answer: option C

Speed of train in m/s = 120 x 5/18 = 300/18 = 50/3 m/s

Distance covered to cross the platform is equal to the sum of length of the train and length of the platform.

So, distance= 150 + 100 = 250 meters

∵ Time = Distance/Speed

= 250 x 3/100

= 750/100

= 7.5 seconds.



7. A train 100 m long is running at a speed of 70 km/h. In how much time will it cross a man walking in the same direction with a speed of 10 km/h?
7 seconds
10 seconds
8 seconds
6 seconds
Answer: option D

Time = Distance/Speed

so the relative speed = (speed of train - speed of man)

∵ Relative Speed = (70-10) = 60 km/hr

∵ Relative Speed in m/s = 60 x 5/18 = 300/18 = 50/3 m/s

Distance covered to cross the man = length of the train (100 meters)

Time = Distance/Speed

= 100 x 3/50

= 300/50 = 6 seconds.



8. Two trains of lengths 120 m and 140 m are moving in the same direction on parallel tracks with speeds of 82 km/h and 64 km/h. In what time will the first train cross the second?
57 seconds
52 seconds
42 seconds
55 seconds
Answer: option B

Time = Distance covered/Speed

In this problem, both the trains are in motion so we will find the relative speed of the train. They are moving in the same direction, so the relative speed is equal to the difference of their individual speeds.

∵ Relative Speed: (82-64) = 18 km/hr

∵ Relative Speed in m/s: 18 x 5/18 = 5 seconds.

Distance covered is equal to the sum of the length of trains: 120+140 = 260 meters

Time = 260/5 = 52 seconds.



9. A train 200 m long takes 12 seconds to pass a man who is running at a speed of 10 km/h in the opposite direction of the train. What is the speed of the train?
50 km/hr
60 km/hr
55 km/hr
52 km/hr
Answer: option A

the speed of train relative to man is the sum of their individual speeds.

Let the speed of train is X km/hr

Then the relative speed will be: (X + 10) km/hr

the relative speed is to divide the distance covered (length of train) by the time taken by the train to cross the man.

∵ Relative Speed = 200/12 = 50/3

∵ Relative Speed in Km/hr = 50/3 x 18/5 = 900/15 = 60 km/hr

⟹ Now, X+10 = 60

⟹ X = 60 − 10 = 50 km/hr



10. A train 125 m long crosses a man traveling in the same direction with a speed of 5 km/h in 10 seconds. The speed of the train is:
61 km/hr
56 km/hr
50 km/hr
54 km/hr
Answer: option C

Speed of the train relative to man = 125/10 m/sec

(25/2) m/sec

( 25/2 x 18/5 ) km/hr

= 45 km/hr.

∵ Let the speed of the train be x km/hr. Then, relative speed = (x - 5) km/hr.

⟹ x - 5 = 45

⟹ x = 50 km/hr.




≪ 1 2 3 4 5 ≫