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?
120 m
240 m
300 m
None of these
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 14 of 28.

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.

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.

Sabira said:   1 decade ago
S = 54*(5/18) = 15m/s.

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.

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.

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.

Vinod Anand said:   1 decade ago
When Speed is =54km/h than 54*5/18.

Speed = 15 m/sec.

Now time are = 30-26 = 16 sec.

The length of the Platform is = 15*16.
= 240 m. (B).

Savitha said:   1 decade ago
@Vinod you have done a mistake 36-20 k be careful while doing.


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