# Problems on Trains

6. A train 240 m long passes a pole in 24 seconds. How long will it take to pass a platform 650 m long?
 A. 65 sec B. 89 sec C. 100 sec D. 150 sec

Explanation:

 Speed = 240 m/sec = 10 m/sec. 24

 Required time = 240 + 650 sec = 89 sec. 10

7. Two trains of equal length are running on parallel lines in the same direction at 46 km/hr and 36 km/hr. The faster train passes the slower train in 36 seconds. The length of each train is:
 A. 50 m B. 72 m C. 80 m D. 82 m

Explanation:

Let the length of each train be x metres.

Then, distance covered = 2x metres.

Relative speed = (46 – 36) km/hr

 = 10 x 5 m/sec 18

 = 25 m/sec 9

 2x = 25 36 9

2x = 100

x = 50.

8. A train 360 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
 A. 40 sec B. 42 sec C. 45 sec D. 48 sec

Explanation:

 Formula for converting from km/hr to m/s:   X km/hr = X x 5 m/s. 18

 Therefore, Speed = 45 x 5 m/sec = 25 m/sec. 18 2

Total distance to be covered = (360 + 140) m = 500 m.

 Formula for finding Time = Distance Speed

 Required time = 500 x 2 sec = 40 sec. 25

9. Two trains are moving in opposite directions @ 60 km/hr and 90 km/hr. Their lengths are 1.10 km and 0.9 km respectively. The time taken by the slower train to cross the faster train in seconds is:
 A. 36 B. 45 C. 48 D. 49

Explanation:

Relative speed = (60+ 90) km/hr

 = 150 x 5 m/sec 18

 = 125 m/sec. 3

Distance covered = (1.10 + 0.9) km = 2 km = 2000 m.

 Required time = 2000 x 3 sec = 48 sec. 125

10. A jogger running at 9 kmph alongside a railway track in 240 metres ahead of the engine of a 120 metres long train running at 45 kmph in the same direction. In how much time will the train pass the jogger?
 A. 3.6 sec B. 18 sec C. 36 sec D. 72 sec

Explanation:

Speed of train relative to jogger = (45 – 9) km/hr = 36 km/hr.

 = 36 x 5 m/sec 18

= 10 m/sec.

Distance to be covered = (240 + 120) m = 360 m.

 Time taken = 360 sec = 36 sec. 10