Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 9)
9.
Two trains are moving in opposite directions @ 60 km/hr and 90 km/hr. Their lengths are 1.10 km and 0.9 km respectively. The time taken by the slower train to cross the faster train in seconds is:
Answer: Option
Explanation:
Relative speed = (60+ 90) km/hr
| = |  |
150 x | 5 |  m/sec |
| 18 |
| = | |
125 | m/sec. |
| 3 |
Distance covered = (1.10 + 0.9) km = 2 km = 2000 m.
| Required time = | |
2000 x | 3 | sec = 48 sec. |
| 125 |
Discussion:
107 comments Page 5 of 11.
Geenee said:
10 years ago
Why km is converted into meter though there all information is in kilometer?
Jyothi said:
10 years ago
km/hr = 1000 m/3600 sec = 5/18 m/sec [1000/3600 = 5/18].
Santhu said:
10 years ago
Km/hr convert meter/sec=5/18 multiple.
Ramya said:
1 decade ago
How 5/18 came? Can you please explain me?
Riyaz said:
1 decade ago
Hi friends. I have one doubt when the trains are moving in opposite direction we add the speed of those trains but why we have to add the length of the two trains. Please explain me.
Sateesh Vudum said:
1 decade ago
For every problem like this you should find relative speed to get solution.
Need of relative speed: we can desire the solution without forming the relation between two quantities either speed or time.
Time = (L1+L2)/(relative speed);
L1-Length of train-1.
L2-Length of train-2.
Need of relative speed: we can desire the solution without forming the relation between two quantities either speed or time.
Time = (L1+L2)/(relative speed);
L1-Length of train-1.
L2-Length of train-2.
Agasthya Rana said:
1 decade ago
Why are we adding speed?
Amrutha said:
1 decade ago
In the above given that:
T = x+y/u+v for opposite direction.
Can you please apply in this problem?
T = x+y/u+v for opposite direction.
Can you please apply in this problem?
Anand said:
1 decade ago
Why 5/18?
ParthShah said:
1 decade ago
Point 1: Trains are running in opposite directions so the slower train will cross the faster one.
Point 2: The time taken by slower train to cross faster train would be equal to the vice versa.
Point 2: The time taken by slower train to cross faster train would be equal to the vice versa.
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