Aptitude - Problems on Trains - Discussion

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.

Guys.. i can suggest u one thng that don't depend entirely on formulas, try

to analyze these type of problems logically..

coming to the prblm..

length of train = 240 mts

time taken to cross reference point(pole) = 24 sec

by the basic formula speed=length/time= (240/24) = 10 m/sec

they are asking the time taken by the train to cross the platform

imagine

------------------------- its a platform
650 m
______________ its train
240 m

train is said to be crossed the platform only if the entire train has pased over from it ryt... so clearly the total length that has to be travel to cross the platform is= (platform length + train length)

i.e. 650+240=890 m/sec

and again from the basic formula time= length/speed = 890/10 = 89 sec

We need to find the time that will take to pass a platform of 650 m.

Therefore, Time = Distance/Speed.
Speed is not given so need to find speed with given values.
Speed = Distance / Time.
= 240 m/24 sec.
= 10 m/sec.

Now we have Distance and Speed to calculate Time that will take to pass 650 m platform.
Time = (650 + 240)m/10 m/sec.
= 890/10 sec.
= 89 sec.

Note : If a train passes a tunnel, bridge, platform then distance covered by train is Length of the train + Length of tunnel (or) bridge (or) platform.

That's why we are adding Length of train + Length of the platform in Distance while calculating Time.

Should not consider the only Length of the platform(650 m).

We need to find the time that will take to pass a platform of 650 m.

Therefore, Time = Distance/Speed.
Speed is not given so need to find speed with given values.
Speed = Distance / Time.
= 240 m/24 sec.
= 10 m/sec.

Now we have Distance and Speed to calculate Time that will take to pass 650 m platform.
Time = (650 + 240)m/10 m/sec.
= 890/10 sec.
= 89 sec.

Note : If a train passes a tunnel, bridge, platform then distance covered by train is Length of the train + Length of tunnel (or) bridge (or) platform.

That's why we are adding Length of train + Length of the platform in Distance while calculating Time.

Should not consider the only Length of the platform(650 m).

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.

Hey, Dude, I am here to clarify your Doubt.
Here Given data is :
Length of the Train = 240m.

Time is taken by the train to cross the pole = 24sec.
so speed of the train = distance/time.
=> 240/24 = 10m/s.

Therefore train speed = 10m/s.
And Length of the platform = 650m.

So we can add the length of train+length of the platform=240+650 = 890m.

bcoz train passes the platform that y we can add both the lengths here.
time is taken by train to cross the platform=total distance/speed.

So 890/10 = 89sec.

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.

The train 240 metres long, passes a stationary point in 24 seconds.

It passes the distance its own length of 240 metres in 24 seconds.

So, it passes 240 metres in 24 seconds.
Its speed is = 240 metres in 24 seconds.
=240 / 24 = 10 metres /second.

To pass a platform of length 650 metres, it should pass the platform and its own length of 240 metres, (to clear the platform),.

So, it should pass 650+240 = 890 metres.

At a speed of 10 metres per second, it will cross 890 metres in 89 seconds.

I have a simple solution.
Speed = distance/time;
240/24 = 10 m/s is speed of train.

Now pltform length is 650 m.
We have speed of train nd platform length.
so, time for crossing platform=length of platform/speed of train(t=d/s),
T(time for crossing platform)=650/10 = 65.

Here 65 is the time taken by the part of engine to cross the platform, not by the entire train.
24 second is time taken by train to reach to the pole + 65 sec is time tacken by train to cross the platform = 89 sec.

As the train crosses the platform, we have to add the length of the train to the platform length. (remember this the train engine is at the platform starting point).

By using the pole concept in the given problem we can find the speed of the train.

Speed=distance*time.

240/24=10sec.

Because, the train to cross the platform, the total length travelled to cross the platform is equal to the length of the train plus length of the platform,

Speed= (240+650) /10.
= 890/10.
= 89.