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 2 of 11.
Anjan said:
1 decade ago
Hi frds. Well I have a doubt. How can a slower train ever cross the faster one?.
Kiran said:
1 decade ago
But can you tell me when we subtract (1.10km-0.9km)it becomes(0.2km)
then how can it becomes 2 km. Please explain.
then how can it becomes 2 km. Please explain.
Hadiyal Jignesh said:
1 decade ago
Kiran There is no subtraction in formula we are adding the 1.10 km + 0.9 km = 2 km
right?
right?
Sathish said:
1 decade ago
How to change 2km = 2000m ?
Sundar said:
1 decade ago
@Sathish
1 km = 1000 m
2 km = 1000 x 2 = 2000m.
1 km = 1000 m
2 km = 1000 x 2 = 2000m.
Himanshu said:
1 decade ago
Is there be any need to convert the speed and distance into mtrs? We could have been done it without converting to mtrs i.e. in kms only.
Himanshu said:
1 decade ago
If the question be:
The time taken by the faster train to cross the slower train in seconds is. ?
What would be the working and answer?
The time taken by the faster train to cross the slower train in seconds is. ?
What would be the working and answer?
Gaurav said:
1 decade ago
@Jyoti:
When slower train will cross the faster train, it means both train has crossed each other , so don't get confused with that.
The question is simply asking when both train will cross each other.For that total distance will be the sum of the lengths of both trains. And total(relative) speed also will be the sum of speeds of both the trains.
When slower train will cross the faster train, it means both train has crossed each other , so don't get confused with that.
The question is simply asking when both train will cross each other.For that total distance will be the sum of the lengths of both trains. And total(relative) speed also will be the sum of speeds of both the trains.
(1)
Surojitsaha said:
1 decade ago
So, you mean time taken by the faster train is also same as time taken by slower train.
Dipti said:
1 decade ago
Relative speed = (60+ 90) km/hr 150 is ok
= 150 x 5/18 m/sec
but how this 5/18 came
could you please discuss on this
= 150 x 5/18 m/sec
but how this 5/18 came
could you please discuss on this
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