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 16 of 26.
Anu said:
10 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.
Vanitha peddireddy said:
4 months ago
Train = 130.
Bridge = x.
Distance = 45,
1000/3600 = 5/18.
45 * 5/18 * 30 = 375,
375 - 130 = 245 = C.
Bridge = x.
Distance = 45,
1000/3600 = 5/18.
45 * 5/18 * 30 = 375,
375 - 130 = 245 = C.
(3)
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:
2 decades 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!
Sumit said:
9 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:
8 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:
2 decades 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:
3 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.
(67)
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