Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 5)
5.
A train passes a station platform in 36 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform?
Answer: Option
Explanation:
| Speed = |  |
54 x | 5 |  m/sec = 15 m/sec. |
| 18 |
Length of the train = (15 x 20)m = 300 m.
Let the length of the platform be x metres.
| Then, | x + 300 | = 15 |
| 36 |
x + 300 = 540
x = 240 m.
Discussion:
276 comments Page 5 of 28.
Jagadeesh said:
1 decade ago
Hey guys u can do like this u can take the diffeerence between times i.e 36-20=16 seconds
u can change 54km/hr as meters 54*5/18=15
16*15=240meters
u can change 54km/hr as meters 54*5/18=15
16*15=240meters
Kirankumar said:
1 decade ago
Hi afkhan according to nick
The train takes to cross it self 20
The remaining 16 for platform
Refer point no 4 in formulae.
The train takes to cross it self 20
The remaining 16 for platform
Refer point no 4 in formulae.
Sid said:
1 decade ago
Satheesh your answer is simply super. Thank you.
Sabarish said:
1 decade ago
@saikiran
here speed of the train given as in km/hr . so first we convert it into m/sec [i.e 54km/hr*(5/18)=15m/sec]. 5/18 is used to convert train speed into m/sec.
Then if you want length of the train means,you;ll use below formula:
Length of the Train=Speed*time
It is general formula in train based questions..
Have a nice day for you..
here speed of the train given as in km/hr . so first we convert it into m/sec [i.e 54km/hr*(5/18)=15m/sec]. 5/18 is used to convert train speed into m/sec.
Then if you want length of the train means,you;ll use below formula:
Length of the Train=Speed*time
It is general formula in train based questions..
Have a nice day for you..
Suresh said:
1 decade ago
Satheesh your answer is very easy and simple way of maintain the problem solution. Thank you.
Sachin kamble said:
1 decade ago
Train passes the plat form in 36 sec and man standing on platform i.e 20 sec so the time 16 sec by 36-20=16 then apply speed=distance/time we have speed 54km/hr that to be converted in to m/sec because we need length in meter. So 54*[5/18] = 15 m/sec.
Then distance = 16*15 = 240.
Then distance = 16*15 = 240.
Vivek said:
1 decade ago
Why we have multiplied with 20 means ... we have to take any one of the reference point. 36sec is train PASSES a station platform so we cant take. but here we can take it because man STANDING on the platform in 20 seconds. STANDING POINT is take it as reference point for calculating lengh of train.
Sanjay punj said:
1 decade ago
Thanks sachin kamble.
Tara said:
1 decade ago
The above answer can be solved by Jagadeesh & Verti given method, i thinkg its also rite.
Manonmani said:
1 decade ago
I also having doubt.
Why we took 20 sec (300=20*15).
Instead of 30sec (450=30*15).
Why we took 20 sec (300=20*15).
Instead of 30sec (450=30*15).
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