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 16 of 25.
Sumit said:
8 years ago
@Guru.
5/18 is here because to converting distance km/h to m/s it's a formula to convert.
5/18 is here because to converting distance km/h to m/s it's a formula to convert.
Sarang said:
7 years ago
Distance = speed*time,
D= 45* 5/18*30,
D= 5*5/2* 30,
D= 5 * 5 * 15 = 375,
D= 375- 130= 245.
D= 45* 5/18*30,
D= 5*5/2* 30,
D= 5 * 5 * 15 = 375,
D= 375- 130= 245.
Sunny said:
1 decade ago
Hey boopathi its simple.
2(130+x)=750
130+x=750/2
130+x=375
x=375-130
Therefore x = 245.
2(130+x)=750
130+x=750/2
130+x=375
x=375-130
Therefore x = 245.
BLESINA DASARI said:
2 years ago
Solution:
45 * 5/18 = 12.5,
12.5 * 30 = 375,
375 - 130 = 245,
So, this is how we get 245.
45 * 5/18 = 12.5,
12.5 * 30 = 375,
375 - 130 = 245,
So, this is how we get 245.
(66)
Lokesh said:
1 decade ago
Actually bridge is a stationary object rite. So speed should be zero. Can u pls explain
Nitin said:
1 decade ago
Why we are subtracting 130 from 375. While train runs on the bridge not off the bridge?
RITESH said:
1 decade ago
I want to ask a simple question, how was to come 25/2 ? please send this answer ASAP.
Boopathi said:
1 decade ago
Hey how is it possible to come.
2 (130 + x) = 750.
X = 245 m.
Please advice me.
2 (130 + x) = 750.
X = 245 m.
Please advice me.
Nathy said:
1 decade ago
Sai's method of solving this problem is too simple and easy to understand. Thanks.
Siva Nandi Reddy said:
1 decade ago
Train length and bridge length is always add thats why we subtracted 130 from 375?
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