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?
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.
D = 72km/h * 26,
D = 72 * 5/18 * 26,
D = 4 * 5 * 26,
D = 20 * 26,
D = 520 - 250 = 270m.
(8)
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.
distance = x+250.
distance = speed x time.
x+250 = 72000m/3600sec x 26sec.
x+250 = 520m,
x = 520m - 250m.
x = 270m.
(7)
Sarang said:
7 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.
D=72km/h*26,
D=72*5/18*26,
D=4*5*26,
D=20*26,
D=520-250=270m.
(4)
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.
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)
Madhav Kulkarni said:
5 years ago
Speed=(L1+L2)/2.
72*(5/18)=(250+L2)/26,
L2=(20*26)-250,
=520-250.
=270.
72*(5/18)=(250+L2)/26,
L2=(20*26)-250,
=520-250.
=270.
(1)
Geetu said:
5 years ago
Why x+250 taken here? Please explain me.
(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)
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.
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)
Dinesh guptha said:
1 decade ago
Hi sonam,
Let me explain about converting km/hr into m/s in detail.
1 km = 1000 meters.
1 hr = 3600 seconds.
1 km/hr = 1000/3600 m/s
= 10/36 m/s
= 5/18 m/s.
Therefore 1 km/hr = 5/18 m/sec.
Let me explain about converting km/hr into m/s in detail.
1 km = 1000 meters.
1 hr = 3600 seconds.
1 km/hr = 1000/3600 m/s
= 10/36 m/s
= 5/18 m/s.
Therefore 1 km/hr = 5/18 m/sec.
(1)
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