Aptitude - Problems on Trains

11. 

A 270 metres long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. What is the length of the other train?

A. 230 m
B. 240 m
C. 260 m
D. 320 m
E. None of these

Answer: Option A

Explanation:

Relative speed = (120 + 80) km/hr

   = 200 x 5 m/sec
18

   = 500 m/sec.
9

Let the length of the other train be x metres.

Then, x + 270 = 500
9 9

x + 270 = 500

x = 230.


12. 

A goods train runs at the speed of 72 kmph and crosses a 250 m long platform in 26 seconds. What is the length of the goods train?

A. 230 m
B. 240 m
C. 260 m
D. 270 m

Answer: Option D

Explanation:

Speed = 72 x 5 m/sec = 20 m/sec.
18

Time = 26 sec.

Let the length of the train be x metres.

Then, x + 250 = 20
26

x + 250 = 520

x = 270.


13. 

Two trains, each 100 m long, moving in opposite directions, cross each other in 8 seconds. If one is moving twice as fast the other, then the speed of the faster train is:

A. 30 km/hr
B. 45 km/hr
C. 60 km/hr
D. 75 km/hr

Answer: Option C

Explanation:

Let the speed of the slower train be x m/sec.

Then, speed of the faster train = 2x m/sec.

Relative speed = (x + 2x) m/sec = 3x m/sec.

(100 + 100) = 3x
8

24x = 200

x = 25 .
3

So, speed of the faster train = 50 m/sec
3

   = 50 x 18 km/hr
3 5

   = 60 km/hr.


14. 

Two trains 140 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time (in seconds) which they take to cross each other, is:

A. 9
B. 9.6
C. 10
D. 10.8

Answer: Option D

Explanation:

Relative speed = (60 + 40) km/hr = 100 x 5 m/sec = 250 m/sec.
18 9

Distance covered in crossing each other = (140 + 160) m = 300 m.

Required time = 300 x 9 sec = 54 sec = 10.8 sec.
250 5


15. 

A train 110 metres long is running with a speed of 60 kmph. In what time will it pass a man who is running at 6 kmph in the direction opposite to that in which the train is going?

A. 5 sec
B. 6 sec
C. 7 sec
D. 10 sec

Answer: Option B

Explanation:

Speed of train relative to man = (60 + 6) km/hr = 66 km/hr.

   = 66 x 5 m/sec
18

   = 55 m/sec.
3

Time taken to pass the man = 110 x 3 sec = 6 sec.
55




Have a question?

Ask your question now !