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 10 of 28.
Carlo said:
1 decade ago
Explanation is right.
Distance = time * speed.
Distance or length = 20 * 15 = 300m.
We can't take 36 * 15 because we already used 36 sec to get 540m
so to get the relative speed:
x + 300 = 540.
x = 240m.
Distance = time * speed.
Distance or length = 20 * 15 = 300m.
We can't take 36 * 15 because we already used 36 sec to get 540m
so to get the relative speed:
x + 300 = 540.
x = 240m.
Tina said:
1 decade ago
Total time = 36sec - 20sec = 16 sec.
Speed = 54*(5/18) = 15 m/sec.
Length = speed * time = 15 * 16 = 240m.
Speed = 54*(5/18) = 15 m/sec.
Length = speed * time = 15 * 16 = 240m.
Udaya said:
1 decade ago
We can also do like this guyz.
Total time taken to cross the platform = 36-20 = 16.
Because the person is in the platform which the train crosses.
Now length= 15*16 = 240m.
Total time taken to cross the platform = 36-20 = 16.
Because the person is in the platform which the train crosses.
Now length= 15*16 = 240m.
Sikkanthar said:
1 decade ago
Nice answers. Here they are using the formula is,
(train length + plat form length) / time = speed.
They are calculating the length of the train by using the given data.
Then substitute all the known values and finally got the result.
(train length + plat form length) / time = speed.
They are calculating the length of the train by using the given data.
Then substitute all the known values and finally got the result.
Sabira said:
1 decade ago
S = 54*(5/18) = 15m/s.
Total time=30-20 = 16.
Length = 15*16 = 240.
Total time=30-20 = 16.
Length = 15*16 = 240.
Bhatu said:
1 decade ago
Friends I think the actual answer is 540m, please tell me anybody it is correct or not?
Dinesh said:
1 decade ago
Man is standing on the platform how can you subtract?
Gaurav said:
1 decade ago
Can we do it on this way.
In 36 second train run 36 x 15 = 540 m.
In 20 second train run 20 x 15 = 300 m.
And the length of platform is 540 - 300 = 240 mtr.
In 36 second train run 36 x 15 = 540 m.
In 20 second train run 20 x 15 = 300 m.
And the length of platform is 540 - 300 = 240 mtr.
Rahul said:
1 decade ago
We can do it like this.
Train run in 36sec, so 36 * 15 = 540. Train run in 20 sec, so 20 * 15 = 300.
Ans: 540 - 300 = 240.
Train run in 36sec, so 36 * 15 = 540. Train run in 20 sec, so 20 * 15 = 300.
Ans: 540 - 300 = 240.
Ramkumar said:
1 decade ago
Speed = 54*(5/18) = 15m/s.
Now time = 36-20 = 16.
Now distance(i.e length) = speed*time.
= 15*16.
= 240m/s.
This is way of correct. Please explain.
Now time = 36-20 = 16.
Now distance(i.e length) = speed*time.
= 15*16.
= 240m/s.
This is way of correct. Please explain.
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