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:
78 comments Page 5 of 8.
Vishal said:
1 decade ago
Not train is add own length + Pass platform length.
E.g: Train length 345.
Platform 456.
Train length + Platform length.
345+456 = 801.
Now you got it.
E.g: Train length 345.
Platform 456.
Train length + Platform length.
345+456 = 801.
Now you got it.
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.
Saiteja said:
1 decade ago
Train speed = 45 km/hr.
= 45*(5/18) = 12.5 m/sec.
140 m long bridge cross in = 140/12.5 = 11.2 sec.
Including train length crossing time i.e. 360/12.5 = 28.8 sec.
Total = 11.2+28.8 = 40 sec.
= 45*(5/18) = 12.5 m/sec.
140 m long bridge cross in = 140/12.5 = 11.2 sec.
Including train length crossing time i.e. 360/12.5 = 28.8 sec.
Total = 11.2+28.8 = 40 sec.
Aditya said:
1 decade ago
From where did 45*(5/18) came please explain?
Prasun jana said:
10 years ago
Speed = 45*(5/18) = 12.5.
= (360+140)/12.5 = 40.
= (360+140)/12.5 = 40.
Syed khamar said:
10 years 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.
Chetan said:
10 years ago
Discussion was very nice it's very clear to all.
Praveena said:
10 years 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?
PANASA HARISH KUMAR said:
9 years 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:
9 years ago
d = s * t = 45 * (5/18) = 12.5.
Total length = 360 + 140/12.5 = 40.
Total length = 360 + 140/12.5 = 40.
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