Aptitude - Problems on Trains - Discussion

Discussion Forum : Problems on Trains - General Questions (Q.No. 12)
12.
A goods train runs at the speed of 72 kmph and crosses a 250 m long platform in 26 seconds. What is the length of the goods train?
230 m
240 m
260 m
270 m
Answer: Option
Explanation:

Speed = 72 x 5 m/sec = 20 m/sec.
18

Time = 26 sec.

Let the length of the train be x metres.

Then, x + 250 = 20
26

x + 250 = 520

x = 270.

Discussion:
39 comments Page 1 of 4.

Abc said:   2 years ago
Distance = Speed * Time.
D = 72km/h * 26,
D = 72 * 5/18 * 26,
D = 4 * 5 * 26,
D = 20 * 26,
D = 520 - 250 = 270m.
(7)

Milly said:   2 years ago
How came 5/18? Please explain to me.
(7)

Smayan said:   2 years ago
Length of train be x.
distance = x+250.
distance = speed x time.
x+250 = 72000m/3600sec x 26sec.
x+250 = 520m,
x = 520m - 250m.
x = 270m.
(7)

Vaibhav vishal said:   4 years ago
@Avn.

The total distance covered by train in order to cross the platform will be only x+250.

This is because the length of platform is given, we only have to find out the length of train. So that's why there will be only one x.

I hope you get it.
(1)

Avn said:   4 years ago
Shouldnt the total distance covered by the train in order to cross the platform be x + 250 + x = 2x + 250? Please anyone explain.
(1)

Geetu said:   5 years ago
Why x+250 taken here? Please explain me.
(1)

Madhav Kulkarni said:   5 years ago
Speed=(L1+L2)/2.

72*(5/18)=(250+L2)/26,
L2=(20*26)-250,
=520-250.
=270.
(1)

Ashok said:   7 years ago
Use this Formula for all train problems.

Train length + object length * hr * 60m * 60se/speed(1000).

26= T+250 * 60 * 60/72000,
250+ 26 * 72000/60 * 60,
520 - 250 = 270.

Ronik patel said:   7 years ago
@All.

Why 72 is multiplied by 5/18?

Ans: Because of unit conversion.....

72 is in kmph and our answer is in the meter so it is required to convert speed from kmph to mph.

I hope, this will help you all.
(1)

Jameel said:   7 years ago
Thanks for your solution @Sarang.


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