Aptitude - Problems on Trains - Discussion

Given answer 89 is correct. I too agree.

@All.

What I understand is the train starting point and cross-platform is 650 meters. The train exit point after crossing the platform is 240 meters so you should add 240 + 650.

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.

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.

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.

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.

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.

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 ANS IS 65 SEC BECAUSE;

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

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