Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 22)
22.
Two goods train each 500 m long, are running in opposite directions on parallel tracks. Their speeds are 45 km/hr and 30 km/hr respectively. Find the time taken by the slower train to pass the driver of the faster one.
Answer: Option
Explanation:
| Relative speed = | = (45 + 30) km/hr | |||||||
|
||||||||
|
We have to find the time taken by the slower train to pass the DRIVER of the faster train and not the complete train.
So, distance covered = Length of the slower train.
Therefore, Distance covered = 500 m.
 Required time = |
 |
500 x | 6 |  |
= 24 sec. |
| 125 |
Discussion:
81 comments Page 6 of 9.
Pallavi said:
8 years ago
The answer is simple. We are converting the 'kilo-meters/hour' value into 'meters/second'.
Let me explain about converting km/hr into m/s in detail.
1 km = 1000 meters.
1 hr = 3600 seconds.
1 km/hr = 1000/3600 m/s
= 10/36 m/s
= 5/18 m/s.
Therefore 1 km/hr = 5/18 m/sec.
Let me explain about converting km/hr into m/s in detail.
1 km = 1000 meters.
1 hr = 3600 seconds.
1 km/hr = 1000/3600 m/s
= 10/36 m/s
= 5/18 m/s.
Therefore 1 km/hr = 5/18 m/sec.
Raju said:
8 years ago
How 125÷6 came in this problem? Please explain.
Nanda Kishor said:
8 years ago
@Raju.
In this problem, the relative speed is 75km/hr.
And to find the answer we have to convert the speed into m/s. So(75*5/18= 125/6m/s).
Hope that this will help you.
In this problem, the relative speed is 75km/hr.
And to find the answer we have to convert the speed into m/s. So(75*5/18= 125/6m/s).
Hope that this will help you.
Ganda said:
8 years ago
Here answer should be 48 explain it with given example let the speed of the first train be 4m/s and second be 1m/s and length of trains be 5/5 m then you should make number line and get two seconds so we must add 5+5 10m and divides by 5m/ (1+4).
Sarang said:
7 years ago
Distance =speed * time,
500=45+30km/h*time,
500=75*5/18*time,
500=75*.277*time,
500=20.7*time,
Time=500/20.7=24s.
500=45+30km/h*time,
500=75*5/18*time,
500=75*.277*time,
500=20.7*time,
Time=500/20.7=24s.
Shree said:
7 years ago
Thanks for explaining the answer.
Shubham said:
7 years ago
The correct answer is 48 sec.
Paul said:
7 years ago
This sum is followed by : t= (a+b)/(u+v).
Where: a is the length of the first train.
b: length of other trains.
u and v are the respective velocity.
Where: a is the length of the first train.
b: length of other trains.
u and v are the respective velocity.
B Kapil said:
7 years ago
The right answer will be 24 sec because here it is talking about the time to pass the driver, so the answer will be 24 sec, not 48sec.
Kineg said:
7 years ago
Can anyone explain to me how the distance came 500?
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