Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 3)
3.
The length of the bridge, which a train 130 metres long and travelling at 45 km/hr can cross in 30 seconds, is:
Answer: Option
Explanation:
| Speed = |  |
45 x | 5 |  m/sec |
= | |
25 | m/sec. |
| 18 | 2 |
Time = 30 sec.
Let the length of bridge be x metres.
| Then, | 130 + x | = | 25 |
| 30 | 2 |
2(130 + x) = 750
x = 245 m.
Video Explanation: https://youtu.be/M_d8WufJWKc
Discussion:
247 comments Page 21 of 25.
Joy said:
8 years ago
=> 45 * 5/18 = 225/18 m/s,
=> 225/18*30 = 375(train can go max distance in 30s).
=> 375-130 = 245.
=> 225/18*30 = 375(train can go max distance in 30s).
=> 375-130 = 245.
Moin ashraf said:
8 years ago
Distance = velocity x time.
130+x = (25/2)x30,
x = 245.
130+x = (25/2)x30,
x = 245.
Rajesh said:
8 years ago
Length= speed * time.
Let the bridge length is 'x' and that x is add to train length.
So 130 + x.
As per formula:
(130+x ) =(45 * {1000/3600}) * 30
=( 45 * (5/18) ) * 30
= (750/2)
(130+x) = 375
x = 375-130
x = 245
x = 245.
Let the bridge length is 'x' and that x is add to train length.
So 130 + x.
As per formula:
(130+x ) =(45 * {1000/3600}) * 30
=( 45 * (5/18) ) * 30
= (750/2)
(130+x) = 375
x = 375-130
x = 245
x = 245.
Aneesanser said:
8 years ago
Thank you for all discussing answer.
Guru said:
8 years ago
Why is 5/18 coming here? Please explain that.
Aadhii said:
8 years ago
Your explanation is meaningful and understandable. Thanks @Kalimuthu.
Sumit said:
8 years ago
@Guru.
5/18 is here because to converting distance km/h to m/s it's a formula to convert.
5/18 is here because to converting distance km/h to m/s it's a formula to convert.
Babool said:
8 years ago
Speed = 45 * 5 m/sec = 25 m/sec.
18 2
Time = 30 sec.
Let the length of the bridge be x metres.
Then, 130 + x = 25.
30 2
2(130 + x) = 750
x = 245 m.
18 2
Time = 30 sec.
Let the length of the bridge be x metres.
Then, 130 + x = 25.
30 2
2(130 + x) = 750
x = 245 m.
Anil Bhadani said:
8 years ago
45 km *30 sec /3600 sec = 375m.
So length of bridge = passes length - length of train = 375m - 130 m = 245m.
So length of bridge = passes length - length of train = 375m - 130 m = 245m.
Tejashwini s said:
8 years ago
Good explanation @Anil Bhadani.
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