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 10 of 24.
Shro said:
1 decade ago
For all those who got doubt why 46-36?
Its because both train are moving in same direction.
So as per the formula when moving in same direction.it should be subtracted.
When moving in opposite direction,it should be added.
Its because both train are moving in same direction.
So as per the formula when moving in same direction.it should be subtracted.
When moving in opposite direction,it should be added.
Shro said:
1 decade ago
We are supposed to find length of each train .
But both train are moving in same direction.
So let the length of each train be x respectively.
So the distace covered will be x+x=2x metres
But both train are moving in same direction.
So let the length of each train be x respectively.
So the distace covered will be x+x=2x metres
Abhishek said:
1 decade ago
Relative speed 46-36= 10 kmph
10 x 5/ 18 = 25/9
in 36 second total distance covered = 100m
100/2= 50 m length of each train.
10 x 5/ 18 = 25/9
in 36 second total distance covered = 100m
100/2= 50 m length of each train.
RAHAMAN said:
1 decade ago
EASIEST WAY
(10*5/18)*36=100/2=50
(10*5/18)*36=100/2=50
Nagarjuna said:
1 decade ago
Length of train is equal to diffence in speeds multiplied by that's all.
46-36=10km/hr.
36sec*10km/hr.
36*10* (5/18) mts/s.
100mts.
46-36=10km/hr.
36sec*10km/hr.
36*10* (5/18) mts/s.
100mts.
Arvind Kumar Sharma said:
1 decade ago
Lets take it as train t1 speed=46*(5/18)=115/9 m/sec.
and similarly train t2's speed= 36*(5/18)=10m/sec.
Now after 36 sec t1 will cover=36*(115/9)=460m
and t2 will cover=36*10=360m
So the difference between their head engine will be=460-360=100m
So the length of trains will 100/2=50 each
and similarly train t2's speed= 36*(5/18)=10m/sec.
Now after 36 sec t1 will cover=36*(115/9)=460m
and t2 will cover=36*10=360m
So the difference between their head engine will be=460-360=100m
So the length of trains will 100/2=50 each
Aparna said:
1 decade ago
Let the train A started at the end of other train B. So, it has to first cover the whole length of the train B and to completely cross B it has to cover additional length of the train A. So, length=2*lenth of each train.
Swapan said:
1 decade ago
Please let me know where does the faster train start.
If the faster train starts behind the slower train the above solution is right otherwise it will be 100.
If the faster train starts behind the slower train the above solution is right otherwise it will be 100.
Anil said:
1 decade ago
Its not mention that trains are started at same point, then how can we solve the problem.
Pooja said:
1 decade ago
How will you subtract speeds. Because here speeds mentioned are the speeds of two different trains not the same train speeds.
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