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 12 of 25.
Vikash Kumar Bharti said:
4 months ago
Given, train length s = 130.
Let, the bridge length is x.
Total passing length = velocity * time.
S + x = vt.
130 + x = 45 * (5/18) * 30.
x = 245m.
Let, the bridge length is x.
Total passing length = velocity * time.
S + x = vt.
130 + x = 45 * (5/18) * 30.
x = 245m.
(23)
Chethan said:
1 decade ago
dis=len of train+bridge length(take a bridge as x)
130+x
speed=45km/hr=45*5/18=25/2
time=30sec
dis=speed*time
130+x=25/2*30
130+x=375
x=245m.
130+x
speed=45km/hr=45*5/18=25/2
time=30sec
dis=speed*time
130+x=25/2*30
130+x=375
x=245m.
Prakash said:
3 years ago
Why are you people adding the bridge distance?
If in case the bridge distance is lesser than the train distance, then how it will be calculated?
If in case the bridge distance is lesser than the train distance, then how it will be calculated?
(19)
Nowsath said:
9 years ago
I have a simple method.
45 * 5/18 equal 12.5 m/s.
Then,
12.5 = x + 130/30 then,
12.5 * 30 = 375.
So,
375 - 130 = 245.
Therefore, x equal 245.
45 * 5/18 equal 12.5 m/s.
Then,
12.5 = x + 130/30 then,
12.5 * 30 = 375.
So,
375 - 130 = 245.
Therefore, x equal 245.
Sanilam Guha said:
4 years ago
(0.130+x) = (45 * 30)/3600.
If assume x is bridge length;
OR, 0.130 + x = 0.375.
OR, X = 0.375 - 0.130.
OR, X = 0.245 KM OR 245 M.
Am I right?
If assume x is bridge length;
OR, 0.130 + x = 0.375.
OR, X = 0.375 - 0.130.
OR, X = 0.245 KM OR 245 M.
Am I right?
(2)
Safina M said:
1 decade ago
Hey Radha,
Cross multiply (139+x)/30=25/2 i.e,
2*(130+x)=30*25.
i.e., 260+2x=750.
2x=750-260.
2x=490.
x=490/2.
Hence, x=245.
Cross multiply (139+x)/30=25/2 i.e,
2*(130+x)=30*25.
i.e., 260+2x=750.
2x=750-260.
2x=490.
x=490/2.
Hence, x=245.
Arup Kumar subudhi said:
4 years ago
Train Speed is 45 km/sec = (45*5)/18 = 25/2 m/s.
= (25*15)/(2*15) m/s,
= 375/30 m/s.
375 m in 30 sec, so bridge length is = 375 - 130 = 245m.
= (25*15)/(2*15) m/s,
= 375/30 m/s.
375 m in 30 sec, so bridge length is = 375 - 130 = 245m.
(2)
Naresh said:
1 decade ago
Simplifying the following equation.
45*30*(5/18) = 15*25 = 375 = length of train + length of bridge.
Length of train = 375-130 = 245.
45*30*(5/18) = 15*25 = 375 = length of train + length of bridge.
Length of train = 375-130 = 245.
Mounish said:
9 years ago
Length = 130 + x.
Speed = 45 km/hr = (45 * 5/18) m/sec.
Time = 30.
Length =Speed * Time.
= 225/18 * 30.
= 375.
x = 375 - 130.
= 245 m.
Speed = 45 km/hr = (45 * 5/18) m/sec.
Time = 30.
Length =Speed * Time.
= 225/18 * 30.
= 375.
x = 375 - 130.
= 245 m.
Surekha said:
8 years ago
How would you say that bridge length would be more that train?
If bridge length is smaller than train means the answer would be vary.
If bridge length is smaller than train means the answer would be vary.
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