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 4 of 24.
Rabiul said:
8 years ago
FASTER Train travels in 36 SECOND
(46 X 5 /18) X 36 = 460 M.
SLOWER Train travels in 36 SECOND
(36 X 5/18) X 36= 360 M.
Therefore 460-360= 100 M (length if both train) as both train travels 36 sec. And as both the trains are equal than the length of each train will be (100/2)= 50 m.
At the point of overtaking by train B in 36 seconds.
(46 X 5 /18) X 36 = 460 M.
SLOWER Train travels in 36 SECOND
(36 X 5/18) X 36= 360 M.
Therefore 460-360= 100 M (length if both train) as both train travels 36 sec. And as both the trains are equal than the length of each train will be (100/2)= 50 m.
At the point of overtaking by train B in 36 seconds.
Ankit said:
10 years ago
I think the answer should be 100 meters, because in question it is not given the starting positions of trains. So we have to assume they started from same point.
Now let the slower train is at rest then the faster train's speed would be 10 km/hr, and it cross the slower train (length) in 36 sec. So the LENGTH = 10km/hr*30 sec = 100 meters.
Now let the slower train is at rest then the faster train's speed would be 10 km/hr, and it cross the slower train (length) in 36 sec. So the LENGTH = 10km/hr*30 sec = 100 meters.
Mohit tiwari said:
9 years ago
In other words, we can say that in this question slowest train is at rest and fast train in moving with speed of 10 km/hr and to pass slow train fast train only needs to pass it's length because both trains start at same point so the distance covered by train in 36 sec is,
10 * (5/18) * 36 = 100m.
So the correct answer is 100 not 50m.
10 * (5/18) * 36 = 100m.
So the correct answer is 100 not 50m.
Indranil Mal said:
2 years ago
Since the length of the two trains are equal then in 36 seconds the trains cross each other.
Relative speed = 46 - 36 = 10kmph.
In 3600sec distance covered=10000m.
Therefore distance covered in 36 secs=10000/3600 * 36 = 100.
As the train covers each other and the length is of equal.
So the actual length of each train = 100/2 = 50m.
Relative speed = 46 - 36 = 10kmph.
In 3600sec distance covered=10000m.
Therefore distance covered in 36 secs=10000/3600 * 36 = 100.
As the train covers each other and the length is of equal.
So the actual length of each train = 100/2 = 50m.
(10)
Hasi said:
1 decade ago
Distance traveled by train =x
2 trains have same length
there are two trains traveled at the same time
means total distance traveled by the train =2x
Relative distance of the train is =(46-36)=10km/hr
but options are given in sec so,we have to convert into m/sec
10*(5/18)=25/9
total distance=speed*time
2x=(25/9)*36
2x=100
x=50
2 trains have same length
there are two trains traveled at the same time
means total distance traveled by the train =2x
Relative distance of the train is =(46-36)=10km/hr
but options are given in sec so,we have to convert into m/sec
10*(5/18)=25/9
total distance=speed*time
2x=(25/9)*36
2x=100
x=50
AMGOTH SRIVASU said:
4 months ago
@All
Speeds of {train1:46km/h},{train2:36km/h}
Across each other in time 36s,
Here the two are in parallel directions travelling where the relative speed of parallel is (train1-train2)/2.
so: length = (t1 - t2)/2 * time.
length= (46km-36km)/2 * 36,
= 10km * 18,
= 10 * (5/18)m*18,
Therefore the length = 50m.
Speeds of {train1:46km/h},{train2:36km/h}
Across each other in time 36s,
Here the two are in parallel directions travelling where the relative speed of parallel is (train1-train2)/2.
so: length = (t1 - t2)/2 * time.
length= (46km-36km)/2 * 36,
= 10km * 18,
= 10 * (5/18)m*18,
Therefore the length = 50m.
(4)
Xyz said:
4 months ago
Length of the train = x.
As both train of equal length = 2x,
Relative speed(faster train-slower train) = (46 - 36) = 10km/hr,
To convert km/hr->m/sec,
10*5/18=25/9 in m/sec.
distance travelled = speed * time.
25/9 * 36 = 100m,
As the total distance covered by both the train is 2x,
2x = 100.
And x = 50(length of each train).
As both train of equal length = 2x,
Relative speed(faster train-slower train) = (46 - 36) = 10km/hr,
To convert km/hr->m/sec,
10*5/18=25/9 in m/sec.
distance travelled = speed * time.
25/9 * 36 = 100m,
As the total distance covered by both the train is 2x,
2x = 100.
And x = 50(length of each train).
(5)
Tamilzhan said:
8 years ago
The relative speed = (46-36)=10km/h.
converted into m/s = 10 * 5/18 = 25/9m/s -------------------------- 46km/h train 1 faster train
(x) 36 sec -------------------------- 36km/h train 2 slower train.
Find out the length of the train (distance) d = s * t.
25/9 * 36 = 100both train.
100/2 find the each train distance,
50.
converted into m/s = 10 * 5/18 = 25/9m/s -------------------------- 46km/h train 1 faster train
(x) 36 sec -------------------------- 36km/h train 2 slower train.
Find out the length of the train (distance) d = s * t.
25/9 * 36 = 100both train.
100/2 find the each train distance,
50.
RADHESHYAM KAMDE said:
6 years ago
Let the length of first train = L.
As we know that trains has equal length;
Therefore L+L = 2L.
And relative speed = 46-36 km/hr (because of the train are going the same direction, so we substrated it).
= 25/9 m/sec.
Time given in question = 36 sec.
We know;
Speed = distance/time.
25/9 = 2L/36,
L = 50 metre.
As we know that trains has equal length;
Therefore L+L = 2L.
And relative speed = 46-36 km/hr (because of the train are going the same direction, so we substrated it).
= 25/9 m/sec.
Time given in question = 36 sec.
We know;
Speed = distance/time.
25/9 = 2L/36,
L = 50 metre.
Basavaraj said:
4 years ago
Answer is 100mtr.
As per the relative speed concept and as per the given question both trains of equal length are at the same point so a faster train has crossed its own length or the length of another one to cross it completely.
So it has to travel x mtr to cross another one with a speed of 10km/hour more.
As per the relative speed concept and as per the given question both trains of equal length are at the same point so a faster train has crossed its own length or the length of another one to cross it completely.
So it has to travel x mtr to cross another one with a speed of 10km/hour more.
(6)
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