Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 11)
11.
A 270 metres long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. What is the length of the other train?
Answer: Option
Explanation:
Relative speed = (120 + 80) km/hr
| = |  |
200 x | 5 |  m/sec |
| 18 |
| = | |
500 | m/sec. |
| 9 |
Let the length of the other train be x metres.
| Then, | x + 270 | = | 500 |
| 9 | 9 |
x + 270 = 500
x = 230.
Discussion:
66 comments Page 3 of 7.
Dalton said:
8 years ago
It's simple and just take it easy.
When two trains running on the same site then relative speed is add, running in opposite site then we subtract it.
When two trains running on the same site then relative speed is add, running in opposite site then we subtract it.
Ramya said:
7 years ago
On cross multiplication we get,
9 (500) =4500.
Then, 9 (270+x), 9 goes to another side.
270+x=4500/9,
270+x=500,
X=500-270.
Finally, we get 230.
9 (500) =4500.
Then, 9 (270+x), 9 goes to another side.
270+x=4500/9,
270+x=500,
X=500-270.
Finally, we get 230.
(2)
Bablu said:
7 years ago
What will happen if both trains are in the same direction as we relative velocity we can subtract but how the equation will come?
Please tell me.
Please tell me.
Pankaj kumar marskole said:
1 decade ago
Time taken crossed the train=length of the both train/length of the speed.
Let length of the 2nd train is x.
9= (270+x)/(100/3+200/9).
X=230.
Let length of the 2nd train is x.
9= (270+x)/(100/3+200/9).
X=230.
Pio Myria said:
5 years ago
Step-1:
Distance = 250m,
Speed = 72*5/18 = 20,
Time = 26 sec.
Step-2:
Formula d=s*t,
250m=20*26,
250m = 520,
M= 520- 250.
m =270 ans.
Distance = 250m,
Speed = 72*5/18 = 20,
Time = 26 sec.
Step-2:
Formula d=s*t,
250m=20*26,
250m = 520,
M= 520- 250.
m =270 ans.
(5)
Sabira said:
1 decade ago
Speed = 120+80 = 200 km/hr.
200* (5/18) = 500/9m/sec.
Total length = 500/9*9.
= 500 m.
500 - 270 = 230 is the other train length.
200* (5/18) = 500/9m/sec.
Total length = 500/9*9.
= 500 m.
500 - 270 = 230 is the other train length.
Sathish said:
8 years ago
Another train's speed and time is already given from that we can calculate the trains length easily why we go for oppostie train?
Nikita said:
8 years ago
Right. But in the question trains are running in opposite side.
So speed is subtracted ie 120-80 = 40.
Am I correct?
So speed is subtracted ie 120-80 = 40.
Am I correct?
(1)
Meenu said:
2 decades ago
In this solution how you are multiplying 5/18 with 200.
I can't understand that wll you please explain me that.
I can't understand that wll you please explain me that.
Kumaresan.P said:
1 decade ago
Hi friends please help me,
How to identify relative speed and average speed and normal train problems?
How to identify relative speed and average speed and normal train problems?
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers