Aptitude - Problems on Trains - Discussion

@Ishan.

You explained very clearly! thank you.

I think the platfr0m length n0 need t0 take. The train thake 8 sec t0 pass the man. After concider the relative speed.

120/ (36*5/18).

This question asks "In how much time will the train pass the jogger".

Here, this rule is wrongly applied in the explanation: "Distance to be covered" = 240 + 120 m (i.e. "train length" and the distance between "jogger and engine".).

As Per the question, the "Distance to be covered" should be 120 m (i.e Train length).

It doesn't make sense why this explanation is wrongly taking into consideration 240m i.e. "Distance between Train engine and Jogger"?

@All.

Hi, I think the question is incorrect because if they are going in the same direction then train already ahead and has high speed than jogger so the train will go away.

Distance= speed * time.
120+240=45-9km/h*time,
360=36km/h*time,
360=36*5/18*time,
360=2*5*time,
360=10*time,
Time=360/10,
Time=36s.

What about the extra distance Jogger has travelled in those 36 seconds?

Why we are considering full length of the platform as 240m?

It is very much possible that the train will cross the jogger before the platform (240m) is fully covered.

Then why total distance= 120m+240m?

Here the equation is (l1+l2)/(v2+v1).

@All.

I have a doubt. The jogger was not static. This means he/she must have covered some distance before the train crosses, all the solutions have not included this issue. Should I neglect that distance or is there anything I am missing.

To me, total distance = train length+ 240 metre+ the joggers covered path.

Is that correct or not. If not please help.

A jogger is a point object so why we consider the platform length?