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:
254 comments Page 12 of 26.
Santosh said:
1 decade ago
No, WRONG ANSWER.
The correct answer is 115M.
X + 0.260km = 45 * 30/(60 * 60),
X + 0.26 = 0.375,
=> X= 0.115 KM = 115METERS.
The correct answer is 115M.
X + 0.260km = 45 * 30/(60 * 60),
X + 0.26 = 0.375,
=> X= 0.115 KM = 115METERS.
Janani said:
1 decade ago
How get 5/18?
Mahi said:
1 decade ago
But here, how do you get 5/18?
Gaurav rana said:
1 decade ago
Why 130 is added to it?
Emme Naresh said:
1 decade ago
Distance = speed/time;.
Let us bridge length = x say, train travelling distance = 130 m.
The total distance is = x + 130,
Speed = 25/2; time = 30sec.
X + 130 = (25/2) 30,
X = 375 - 130 = 245.
Let us bridge length = x say, train travelling distance = 130 m.
The total distance is = x + 130,
Speed = 25/2; time = 30sec.
X + 130 = (25/2) 30,
X = 375 - 130 = 245.
Sidhartha said:
1 decade ago
The train has to cover twice it's own length and the length of the bridge to cross the bridge so the answer provided is wrong.
It has to be 2x + 130 = 375.
Hence 2x = 245.
X = 122.50m = length of the train.
It has to be 2x + 130 = 375.
Hence 2x = 245.
X = 122.50m = length of the train.
Sandeep said:
1 decade ago
It is easy,
Train length = 130mtr,
Speed = 45km/hr,
Time = 30sec.
First:-
Converting the speed:- 45*5/18 = 12.5,
Then, total distance = speed * time.
= 12.5 * 30 = 375.
Therefore, the length of bridge = 375 - 130 = 245.
Train length = 130mtr,
Speed = 45km/hr,
Time = 30sec.
First:-
Converting the speed:- 45*5/18 = 12.5,
Then, total distance = speed * time.
= 12.5 * 30 = 375.
Therefore, the length of bridge = 375 - 130 = 245.
Nowsath said:
1 decade 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.
Maanvi said:
1 decade ago
@Naveen Kumawat.
Nice description to understand the problem.
Nice description to understand the problem.
Rekha said:
1 decade ago
Hii @Sai.
Why did you subtract the two things that is length and speed?
Why did you subtract the two things that is length and speed?
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