Aptitude - Problems on Trains - Discussion

WHY NOT 65?
We got train speed =10.
Then we can directly find the time right?
i.e time = 65 because t=d/s=>650/10 = 65.

To solve this problem, we need to first determine the speed of the train. We can use the formula:

Speed = Distance/Time.

From the given information, we know that the length of the train is 240 meters and it passes a pole in 24 seconds. Therefore, the speed of the train is:

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

Now, we need to find out how long it will take for the train to pass a platform that is 650 meters long. Let's assume that the front of the train just reaches the beginning of the platform at time t=0.

As the train passes over the entire length of the platform, it will cover a distance equal to the sum of the length of the train and the length of the platform.
Total distance to be covered = 240 + 650 = 890 meters

To find the time taken for the train to cover this distance, we can use the formula:

Time = Distance / Speed

Time = 890 / 10
Time = 89 seconds

Therefore, it will take the train 89 seconds to pass a platform that is 650 meters long.

I THINK ANS IS 65 SEC BECAUSE;

Directly calculate the answer;
240 = 24,
650 = X.

Cross multiplication.
240X = 15600.
X = 15600/240.
X = 65 Sec.

To solve this, we need to consider the additional distance the train needs to cover to pass the platform.

First, let's find the speed of the train:

Speed = Distance/Time.
Speed = 240 m/24 s.
Speed = 10 m/s.

Now, the train needs to cover the length of the platform (650 m) plus its length (240 m) relative to the platform. So, the total distance to cover is 650 m + 240 m = 890 m.

Time = Distance/Speed.
Time = 890 m/10 m/s.
Time = 89 seconds.

So, it will take 89 seconds for the train to pass the platform.

Hi friends,

I tell you the exact reason for why we will and 240 with the plate from length.

Because after 65 seconds the head only reach the last point of the palate form but if the train crosses the plate form then the train will go 240 m ahead so the total meter will be 890. Or you want to calculate time.

So, the time will be 65 s to the platform and another 24 s to cross that platform.

So, it can also add as 65 s + 24 s = 89 s.

Why did we add 240 to 650?

Since we only want to find the time taken to cover 650m.

Anyone, please explain me.

I think the length of a platform is greater than the length of the trian so to pass the platform we should be adding each lengths.

The length of the train = 240m.
time to cross the pole = 24sec.
Length of the station =650m.

so,
The speed of the train = length of the train /time to cross the pole * 18/5.
So,
= 240/24*18/5
= 10*18/5
= 180/5.
The speed of the train = 36km/h.

And the time to cross the station = 240+650/36*18/5.
= 890*18/36*5
= 16020/180.
Final answer = 89sec.
So, option B is the right answer.

Here is the solution

Just apply required time formula.
Required time = distance /speed.

In this case, train Len = 240 + platform = 650/speed.
And req tiime = 240 + 650/10 = 89 m/s thats it.

The train is 240 meters long, and the platform is 650 meters long.

When a train passes a platform, it must cover both its own length and the length of the platform.

So total distance=240 + 650 = 890meters.