Aptitude - Problems on Trains - Discussion

I believe the right answer is 65 Sec.

Because train speed is 10m/Sec and to cross 650-meter bridge it took 65 sec to pass that.

I also think that 65 is the correct answer.

Why can't the answer be 65 according to my explanation?

Speed of the train=(distance /time).

Hence,
240 ÷ 24 =10.
Speed of train is 10 m/s.
Time =distance /speed of the train.
For a 650m platform hence distance is 650.
Time=650m/10m/s.

Hence,
Time =65 sec.

I think we don't need to add both the meters of the platform.

Speed = total (distance/time).
240/24sec = 10 ms.
So, 650/10ms = 65 sec.

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.

The solution is correct.

If we don't add 240 we will get only the time taken for the engine to travel and not the entire train.

So we have to add it.

Please let me know about the solution.

I'm not getting this. someone help me.

65 answer is correct.

I too get the answer as 65.

Pole:
Speed = lengh/time.
= 240/24,
= 10m/s.
Platform:

Time = length/speed.
= (240 + 650)/10,
= 89s.