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:
249 comments Page 15 of 25.
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.
Imthiyaz ahmed said:
1 decade ago
25 meters per 2 sec, 1 sec = 12.5 *30sec = 375-130 = 245 very simple and very fast way to tackle the problem.
Akhil said:
9 years ago
Hi, can anyone tell me how to solve these type of problems?
I'm a just a beginner in maths. Please help me.
I'm a just a beginner in maths. Please help me.
Joy said:
9 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.
Vaibhav mittal said:
8 years ago
Total distance covered by train in crossing the bridge = (25/2) *30=375.
Length of bridge = 375-130 =245.
Length of bridge = 375-130 =245.
Arman said:
9 years ago
In 30 second train goes= 45 x 1000 x 30 / 60 x 60 = 375 .
Bridge length = 375 - 130 = 245. Ans. 245.
Bridge length = 375 - 130 = 245. Ans. 245.
Anu said:
9 years ago
130 + x/30 = 25/2.
2(130 + x) = 25 * 30,
260 + 2x = 750,
2x = 750-260,
2x = 490,
x = 490/2,
x = 245m.
2(130 + x) = 25 * 30,
260 + 2x = 750,
2x = 750-260,
2x = 490,
x = 490/2,
x = 245m.
Karthick said:
1 decade ago
Formula is = (Length of the train + Length of the object)=(Speed of the train* Time of the object).
Sundaram said:
1 decade ago
Because train cross the bridge so we must add the length then only we will get the bridge length.
Madhu said:
1 decade ago
We should convert km/hr to m/sec, so we should multiply the 45km/hr by 5/18,then we get 25m/sec.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers