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 18 of 24.
Santu said:
9 years ago
I don't understand last 3 lines. Can anyone explain last 3 lines, that how much get answer 50?
Amjad Raja said:
9 years ago
Why considered only 36 in the above step?
Jaganmohanreddy said:
9 years ago
@All.
Refer Rajkumar explanation, he explained very well.
Thanks @Rajkumar.
Refer Rajkumar explanation, he explained very well.
Thanks @Rajkumar.
AMANI said:
9 years ago
Please explain it, easily. I can't able to do it.
Rkb said:
9 years ago
T = (L1 + L2)/(S1 + S2),
T * (S1 - S2) = L1 + L2,
36 * 10 * 5/18 = L1 + L2,
100 = L1 + L2.
Given that L1 = L2.
Then,
2L1 = 100.
L1 = 50.
T * (S1 - S2) = L1 + L2,
36 * 10 * 5/18 = L1 + L2,
100 = L1 + L2.
Given that L1 = L2.
Then,
2L1 = 100.
L1 = 50.
Mritika said:
9 years ago
Why have you taken the relative speed here? Please explain.
Nandhu said:
9 years ago
Here, two trains are equal length & same direction but speed is different that's why we calculate the relative speed = u - v.
Saran kamaraj said:
9 years ago
As per the given condition, the faster train crosses the slower train. So it means that.
First,
The fast train crosses the slow train of distance x metre.
Second,
Note (the fast train is not a point,). So it has a length of x meter to cross.
Finally x + x = 2X.
Hope you get it.
First,
The fast train crosses the slow train of distance x metre.
Second,
Note (the fast train is not a point,). So it has a length of x meter to cross.
Finally x + x = 2X.
Hope you get it.
Nikhita said:
8 years ago
Length of both the trains is x+x = 2xkm/hr.
Relative speed = 46-36 = 10km/hr.
Time = 36 sec.
L= 10 * (5/18) * 36.
= 100,
2l= 100,
L= 100/2,
L= 50.
Relative speed = 46-36 = 10km/hr.
Time = 36 sec.
L= 10 * (5/18) * 36.
= 100,
2l= 100,
L= 100/2,
L= 50.
Ishwar shrestha said:
8 years ago
46-36 = 10,
10*5/18 = 2.77,
2.77*36s = 100,
So, the length of train is 100/2 = 50m.
10*5/18 = 2.77,
2.77*36s = 100,
So, the length of train is 100/2 = 50m.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers