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 6 of 24.
Akanksha said:
1 decade ago
Relative speed, u-v = 10 = 10*(5/18) = 25/9 m/s.
We know that, t = a+b/u-v.
And time of crossing the slower train is given, i.e. = 36.
Also length of both is same so a = b,
So, 2a/(25/9) = 36, which results a = 50 and as b is equal to a, hence b = 50 as well.
We know that, t = a+b/u-v.
And time of crossing the slower train is given, i.e. = 36.
Also length of both is same so a = b,
So, 2a/(25/9) = 36, which results a = 50 and as b is equal to a, hence b = 50 as well.
Raghavendra said:
2 years ago
It's a simple calculation, in the above question mention that is found out the length of each train.
Formula:
Length= speed ×time.
Speed = 46-36 = 10 ×5/18 = 2.7777.
Time = 36 seconds.
Then,
Length = 2.7777 × 36.
Length = 100 m.
Length of each train = 50m.
Formula:
Length= speed ×time.
Speed = 46-36 = 10 ×5/18 = 2.7777.
Time = 36 seconds.
Then,
Length = 2.7777 × 36.
Length = 100 m.
Length of each train = 50m.
(100)
Edwin said:
1 decade ago
@Sandy.
I was confused too but I figured it out.
They use km/hr in the first place, and want to convert km/hr to m/sec.
Which is 100(m)/360(sec) (As we know that meter is 100 and sec is 60x60 in hour).
Therefore it will be 5/18 m/sec.
Hope you get it.
I was confused too but I figured it out.
They use km/hr in the first place, and want to convert km/hr to m/sec.
Which is 100(m)/360(sec) (As we know that meter is 100 and sec is 60x60 in hour).
Therefore it will be 5/18 m/sec.
Hope you get it.
Kiran H said:
7 years ago
(Length of a train+Length of the train)/(time is taken by the train to cover the length) = Relative speed of two trains.
Let X be the length of the train.
(X+X)/36 = (46-36) {in km/hr convert it into m/s),
2X/36 = 10*(5/18),
X/18 = 50/18.
Therefore X= 50.
Let X be the length of the train.
(X+X)/36 = (46-36) {in km/hr convert it into m/s),
2X/36 = 10*(5/18),
X/18 = 50/18.
Therefore X= 50.
Heamnath said:
1 decade ago
Trains are running in same direction so the relative speed is different.
Speed of train 1 - speed of train 2.
46 - 39 = 10 Km/hr.
Convert Km/hr to m/sec.
10* 5/18 = 5/3.
Now multiply with faster train cross time ie 36 with obtained value.
36*5/3 = 50m.
Speed of train 1 - speed of train 2.
46 - 39 = 10 Km/hr.
Convert Km/hr to m/sec.
10* 5/18 = 5/3.
Now multiply with faster train cross time ie 36 with obtained value.
36*5/3 = 50m.
Vinod jaddu and mani said:
1 decade ago
Length of the train = X.
Equal length of 2 trains = 2X.
If same direction = u-v = (46-36)km/hr = 10km/hr.
Speed = (Distance or length)/Time.
10 km/hr = 2X/36 sec.
(10*5/18) m/sec = 2X/36 sec.
X = 50 sec answer.
(Note : if opposite direction = u+v).
Equal length of 2 trains = 2X.
If same direction = u-v = (46-36)km/hr = 10km/hr.
Speed = (Distance or length)/Time.
10 km/hr = 2X/36 sec.
(10*5/18) m/sec = 2X/36 sec.
X = 50 sec answer.
(Note : if opposite direction = u+v).
Thimothy said:
1 year ago
Let the speed be 46 & 36 kmph are travel in the same direction so (46-36) = 10 Kmph then change in m/s.
So, 10×5/18 = (25/9)M/S
Distance=speed * time.
They asking the length of each train(2 L )
Distance= speed×time
2 L = (25/9) ×36
2 L = 100
L = 50.
So, 10×5/18 = (25/9)M/S
Distance=speed * time.
They asking the length of each train(2 L )
Distance= speed×time
2 L = (25/9) ×36
2 L = 100
L = 50.
(43)
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.
Subba said:
6 years ago
@Sunny.
We know that speed = distance /time, here apply the same, but here since two trains are moving in the same direction relative speed comes and it is 10km/hr.
Then distance = 10 * 5/18 * 36 = 100metres.
Therefore, 2x = 100 and hence x = 50m each.
We know that speed = distance /time, here apply the same, but here since two trains are moving in the same direction relative speed comes and it is 10km/hr.
Then distance = 10 * 5/18 * 36 = 100metres.
Therefore, 2x = 100 and hence x = 50m each.
Madhav said:
6 years ago
Since they are moving in same direction relative speed is;
46-36=10Km/h= 10*(5/18)= 2.77m/s.
Relative Speed is =2.77m/s.
Speed=Distance/Time.
Distance=Speed*time=2.77*36=99.9==100.
Here 2 train having equal length = D=L=l+l=2l.
2l=100
so l=50.
46-36=10Km/h= 10*(5/18)= 2.77m/s.
Relative Speed is =2.77m/s.
Speed=Distance/Time.
Distance=Speed*time=2.77*36=99.9==100.
Here 2 train having equal length = D=L=l+l=2l.
2l=100
so l=50.
(1)
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