Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 8)
8.
A train 360 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
Answer: Option
Explanation:
| Formula for converting from km/hr to m/s: X km/hr = |  |
X x | 5 |  |
m/s. |
| 18 |
| Therefore, Speed = | |
45 x | 5 | m/sec |
= | 25 | m/sec. |
| 18 | 2 |
Total distance to be covered = (360 + 140) m = 500 m.
| Formula for finding Time = | |
Distance | |
| Speed |
 Required time = |
|
500 x 2 | sec |
= 40 sec. |
| 25 |
Discussion:
79 comments Page 3 of 8.
Syed khamar said:
1 decade ago
S = 45*5/18 => 25/2.
Now train passes platform = 360+140/25/2.
= 500*2/25.
= 40 sec.
Now train passes platform = 360+140/25/2.
= 500*2/25.
= 40 sec.
Praveena said:
1 decade ago
Why should we add 360 and 140?
A train of length 360 is moving on 140 m bridge. It is not covering 360 m distance and 140 m distance. Then why should we add two lengths?
A train of length 360 is moving on 140 m bridge. It is not covering 360 m distance and 140 m distance. Then why should we add two lengths?
DHANASURIYA M G said:
1 month ago
Agree, the train will take 40 seconds to pass the bridge.
PANASA HARISH KUMAR said:
1 decade ago
Train long = 360m.
Speed 45*5/18 = 12.5m/sec.
Bridge long = 140m.
Time = ?
Speed = Distance/Time
12.5 = 360 + 140/time.
Time = 40sec.
Speed 45*5/18 = 12.5m/sec.
Bridge long = 140m.
Time = ?
Speed = Distance/Time
12.5 = 360 + 140/time.
Time = 40sec.
Virang soni said:
10 years ago
d = s * t = 45 * (5/18) = 12.5.
Total length = 360 + 140/12.5 = 40.
Total length = 360 + 140/12.5 = 40.
Anonymous said:
10 years ago
In this question, the length of the bridge is shorter than that of the train. Then why we go for adding the two lengths?
Joydeep mukherjee said:
1 decade ago
There are no starting and end point mentioned in the question.
Whenever, you get this type of question, just.
Total length = 360+140 m = 500 m.
Whenever, you get this type of question, just.
Total length = 360+140 m = 500 m.
Shruthi Bhosle said:
10 years ago
We should find time only for distance of 140m long, why we add (360 + 140).
Uzair said:
10 years ago
What about this?
What is the speed of a 140 m long train cross a 1 km bridge in 12 sec?
What is the speed of a 140 m long train cross a 1 km bridge in 12 sec?
Aishwarya said:
10 years ago
What about this?
Let time be x sec.
Length of the train = 360/x,
Length of the bridge = 140m,
Required time = (360+140)/x,
Which is , x = 500m,
Speed= (45 * 5/18) = 25/2 m/sec,
Time = distance/ time,
500 * 25/2 = 40sec.
Is this method right?
Let time be x sec.
Length of the train = 360/x,
Length of the bridge = 140m,
Required time = (360+140)/x,
Which is , x = 500m,
Speed= (45 * 5/18) = 25/2 m/sec,
Time = distance/ time,
500 * 25/2 = 40sec.
Is this method right?
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers