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 8 of 8.
Sreee said:
5 years ago
Please explain to me why we are adding train length and bridge length. The train is moving on the bridge only.
And they asked only the time taken to move on the bridge.
Please explain to me in detail.
And they asked only the time taken to move on the bridge.
Please explain to me in detail.
Aakriti said:
5 years ago
@Sreee,
According to question, the train should cross the bridge ie. 360m long train should cross 140m long bridge.
Hence, we should add 360 and 140 for total length.
According to question, the train should cross the bridge ie. 360m long train should cross 140m long bridge.
Hence, we should add 360 and 140 for total length.
(6)
Anushiya said:
3 years ago
Aakriti.
Suppose I take the length as 140 only then what happened? Please explain me.
Suppose I take the length as 140 only then what happened? Please explain me.
(5)
Disha patel said:
2 years ago
How 25/2? Please explain.
(18)
Dasari Monica Lucy said:
2 years ago
Given:
Distance of train = 360m,
Speen = 45km/hr,
Distance of bridge = 140m,
45×5/18=12.5
360+140=500
T=D/S =500/12.5.
T= 40.
Distance of train = 360m,
Speen = 45km/hr,
Distance of bridge = 140m,
45×5/18=12.5
360+140=500
T=D/S =500/12.5.
T= 40.
(20)
Paschal said:
2 years ago
For a train to cover any distance, I believe it must first cover(move) its length, that is why we have to add the train length (distance) and that bridge which is static which also the train has to cover.
Correct me If I am wrong.
Correct me If I am wrong.
(9)
Samama Javaid said:
1 year ago
Speed of train = v = 45km/h = 45 × 1000/3600 = 25/2 m/s,
Length of Train= S¹= 360m,
Length of Bridge=S²= 140 m,
Time taken = t1= ?
Time taken = t2=?
Solution :
t1 = S¹/v = 360×2/25 = 28.8 s.
t2 = S2/v = 140 × 2/25= 11.2 s.
Total time taken = t1 + t2= 28.8 + 11.2.
t= 40s.
Length of Train= S¹= 360m,
Length of Bridge=S²= 140 m,
Time taken = t1= ?
Time taken = t2=?
Solution :
t1 = S¹/v = 360×2/25 = 28.8 s.
t2 = S2/v = 140 × 2/25= 11.2 s.
Total time taken = t1 + t2= 28.8 + 11.2.
t= 40s.
(4)
Keanu said:
1 year ago
Nice answer. Thanks all.
(4)
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