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 3 of 24.
Appu said:
1 decade ago
Hello Friends,
If 2 trains of length a and b moving in same direction at u,v.Then the time taken by the faster train to cross the slower train is =(a+b)/(u-v)sec.
So here,Time=36sec and u+v=25/9m/sec
Then the formula is,36=(a+b)/(925/9)
a+b=100
Now we get a=50 and b=50
I think ur doubt is clear now
If 2 trains of length a and b moving in same direction at u,v.Then the time taken by the faster train to cross the slower train is =(a+b)/(u-v)sec.
So here,Time=36sec and u+v=25/9m/sec
Then the formula is,36=(a+b)/(925/9)
a+b=100
Now we get a=50 and b=50
I think ur doubt is clear now
Mega said:
1 decade ago
Why we are taking 2x?
Aditya gangwar said:
1 decade ago
Because both trains are of equal length, mentioned in question. So lets take length=x, then to cross another train of same length i.e. x. First train have to cover distance of x+x.
Thats why he has taken 2x.
Thats why he has taken 2x.
Sunayana said:
1 decade ago
@appu. I understand your way of explaining. Its clear my doubts. Thanks.
Prajwal said:
1 decade ago
You have taken 2x/36.
Is it the speed of the slower train or the time taken to overtake?
Is it the speed of the slower train or the time taken to overtake?
M.chandrababu said:
1 decade ago
Please explain how to take distance covered=2x meters.
Suganthan.m said:
1 decade ago
Distance=sum of length of two trains.
How it is please anyone explain.
How it is please anyone explain.
P sudhakar said:
1 decade ago
Why did take the differences of speed?
Tintu said:
1 decade ago
Cant we do like:
relatv speed=10km/hr
Time=36 sec=.6hr
Then 2x distance is given by 10*.6 hours=6hrs
So x=3hrs
relatv speed=10km/hr
Time=36 sec=.6hr
Then 2x distance is given by 10*.6 hours=6hrs
So x=3hrs
Anne87 said:
1 decade ago
Good day! I just want to know why you used 2X/36? why did you used 36? Thank you!
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