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 15 of 25.
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:
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.
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.
Suren said:
1 decade ago
@Sai.
Your method is fantastic and very easy to understand. Great job! keep it up man. Thanks!
Your method is fantastic and very easy to understand. Great job! keep it up man. Thanks!
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers