# Problems on Trains - Aptitude Questions and Answers - RejinpaulPlacement

29.
A 300 metre long train crosses a platform in 39 seconds while it crosses a signal pole in 18 seconds. What is the length of the platform? [Bank P.O. 2002]

Solution:   Speed of the train = (300/18) m/sec = (50/3) m/sec.

Let the length of the platform be x metres.

Then, (x + 300) / 39 = 50/3
=> 3(x + 300) = 1950
=> x = 350 m.
30.
A train speeds past a pole in 15 seconds and a platform 100 m long in 25 seconds. Its length is: [R.R.B. 2003]

Solution:   Let the length of the train be x metres and its speed be y m/sec.

Then, x/y = 15
=> y = x/15

Therefore, (x + 100) / 25 = x/15
=> x = 150 m
31.
A train moves past a telegraph post ands a bridge 264 m long in 8 seconds and 20 seconds respectively. What is the speed of the train? [S.S.C 2004]

Solution:   Let the length of the train be x metres and its speed by y m/sec.

Then, x/y = 8
=> x= 8y

Now, (x + 264) / 20 = y
8y + 264 = 20 y
y = 22.

Therefore, Speed = 22 m/sec
= (22 * (18/5)) km/hr
= 79.2 km/hr.
32.
A train takes 18 seconds to pass completely through a station 162 m long and 15 seconds through another station 120 m long. The length of the train is:

Solution:   Let the length of the train be x metres.

(x + 162) / 18 = (z + 120) / 15
=> 15(x + 162) = 18(x+120)
=> x = 90 m
33.
How many seconds will a 500 metre long train take to cross a man walking with a speed of 3 km/hr in the direction of the moving train if the speed of the train is 63 km/hr? [S.S.C 2000]

Solution:   Speed of train relative to man = (63 – 3) km/hr = 60 km/hr.
=(60 * (5/18)) m/sec
= (50/3) m/sec

Time taken to pass the man = (500 * (3/50)) sec = 30 sec.
34.
A jogger running at 9 kmph along side a railway track is 240 metres ahead of the engine of a 120 metre long train running at 45 kmph in the same direction. In how much time will the train pass the jogger? [IGNOU 2003]

Solution:   Speed of the train relative to jogger = (45 – 9) km/hr = 36 km/hr
= (36 * (5/18)) m/sec
= 10 m/sec.

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

Time taken = (360/10) sec = 36 sec.
35.
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? [M.A.T 2002]