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 20 of 25.
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.
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.
Harry said:
9 years ago
Speed is 45km/hr
Let's make it to seconds.
(45/3600) * 1000,
=12.5 m in 1sec.
Now let's see it in 30 sec i.e 12.5 * 30 = 375.
So in 30 secs it travels 375 but trains length is 130.
375 - 130 = 245m.
Let's make it to seconds.
(45/3600) * 1000,
=12.5 m in 1sec.
Now let's see it in 30 sec i.e 12.5 * 30 = 375.
So in 30 secs it travels 375 but trains length is 130.
375 - 130 = 245m.
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.
Amit said:
9 years ago
Here, v = 45 km/hr = 45 * (1000/3600) = 25/2 m/s.
T = 30s.
S = vt = (25/2) * 30 = 375 m.
Now, L = 375 - 130 = 245 m (Ans).
T = 30s.
S = vt = (25/2) * 30 = 375 m.
Now, L = 375 - 130 = 245 m (Ans).
RAGHURAM S said:
9 years ago
How 25/2 came?
45 * 5/18 = 25/2?
How?
45 * 5/18 = 25/2?
How?
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.
Subhra said:
9 years ago
L = 45 x 5/18 x 30 = 375 - 130 = 245m.
Anonimy said:
9 years ago
Speed is 45km/hr.
Let's make it to seconds.
(45/3600) * 1000,
=12.5 m in 1sec.
Now let's see it in 30 sec i.e 12.5 * 30 = 375.
So, in 30 secs it travels 375 but trains length is 130.
375 - 130 = 245m.
Let's make it to seconds.
(45/3600) * 1000,
=12.5 m in 1sec.
Now let's see it in 30 sec i.e 12.5 * 30 = 375.
So, in 30 secs it travels 375 but trains length is 130.
375 - 130 = 245m.
Sanjeev said:
8 years ago
Speed = 45 x 5/18 m/sec = 25/2 m/sec.
How it is calculated?
Please explain.
How it is calculated?
Please explain.
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