Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 7)
7.
Two trains of equal length are running on parallel lines in the same direction at 46 km/hr and 36 km/hr. The faster train passes the slower train in 36 seconds. The length of each train is:
Answer: Option
Explanation:
Let the length of each train be x metres.
Then, distance covered = 2x metres.
Relative speed = (46 - 36) km/hr
| = |  |
10 x | 5 |  m/sec |
| 18 |
| = | |
25 | m/sec |
| 9 |
 |
2x | = | 25 |
| 36 | 9 |
2x = 100
x = 50.
Discussion:
232 comments Page 16 of 24.
Deepu said:
1 decade ago
Should be mentioned that the faster train started behind the slower train.
Sita said:
1 decade ago
What is relative speed?
Shoeb said:
1 decade ago
In the question it's clearly mentioned two trains are of same length.
So we can use formula , two trains or two objects bodies are moving in the same direction at u m/s and v m/s, where u > v, then their relative speed is = (u - v) m/s.
* So 46-36=10km/hr.
* 10 *5/18 : 25/9
* 25/9*36 :.100 ( both train )
* 100/2=50 each train.
Thanks.
So we can use formula , two trains or two objects bodies are moving in the same direction at u m/s and v m/s, where u > v, then their relative speed is = (u - v) m/s.
* So 46-36=10km/hr.
* 10 *5/18 : 25/9
* 25/9*36 :.100 ( both train )
* 100/2=50 each train.
Thanks.
Akshay said:
1 decade ago
Use formula
L=length S=Speed
(L1+L2)/(S1-S2)=Time taken by fast train to cross slow train
Let length of train be x
Relative speed = (46-36) * 5/18 m/s =50/18
(x+x)/(50/18) = 36
2x/50=2
2x=100
x=50.
L=length S=Speed
(L1+L2)/(S1-S2)=Time taken by fast train to cross slow train
Let length of train be x
Relative speed = (46-36) * 5/18 m/s =50/18
(x+x)/(50/18) = 36
2x/50=2
2x=100
x=50.
Paddy said:
1 decade ago
If both are of same length but time taken by A to cross B is given i.e 36 minutes, it does not mean that the B train is at Rest.
B is also moving so total distance cover by A = length of A + length of B + some distance after starting.
Total dist travel by B = 360 m
Total dist travel by A = 460 m
Therefore diff is 100 m
i.e. Length of train A or B
B is also moving so total distance cover by A = length of A + length of B + some distance after starting.
Total dist travel by B = 360 m
Total dist travel by A = 460 m
Therefore diff is 100 m
i.e. Length of train A or B
Thanga said:
1 decade ago
In the question clearly mentioned two trains are same length.
So 46 - 36 : 10
10 *5/18 : 25/9
25/9*36 :.100
So both are 100 meters.
So each train 50 meters.
So 46 - 36 : 10
10 *5/18 : 25/9
25/9*36 :.100
So both are 100 meters.
So each train 50 meters.
Mukesh said:
1 decade ago
Whether the trains are in same or in opposite directions we are to add the lengths of trains for covering distances you can check it.
The answer is correct.
The answer is correct.
Selvan said:
1 decade ago
If slower train speed is given means what can I do?
Narottam said:
1 decade ago
The correct answer is 100 m. because the distance travel by faster train in 36 sec is 460 m
and distance travel by the slower train in 36 sec is 360 sec
so the answer is the difference of distance travel by the both train
(460-360)=100m
see practical example following
&&&&&&&& faster train
@@@@@@@@ smaller train
after 36 sec
|......460 m..&&&&&&|
|..360 m @@@@@@..|
so actual result is 100.
and distance travel by the slower train in 36 sec is 360 sec
so the answer is the difference of distance travel by the both train
(460-360)=100m
see practical example following
&&&&&&&& faster train
@@@@@@@@ smaller train
after 36 sec
|......460 m..&&&&&&|
|..360 m @@@@@@..|
so actual result is 100.
Santosh said:
1 decade ago
See.
Please read question once again, the faster train will overtake slower train in 36 seconds, both trains length are same, then sure faster and slower train are not in one position and also understand faster train is 36second behind the slower train.
Please read question once again, the faster train will overtake slower train in 36 seconds, both trains length are same, then sure faster and slower train are not in one position and also understand faster train is 36second behind the slower train.
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