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 6 of 25.
Nattu said:
2 decades ago
But crossing chould mean the whole train should be off the bridge right? So why should we subtract the length of the train?
Rahul said:
2 decades ago
@deepika @nattu
speed= train length + bridge length
----------------------------
time taken to cross
we know train length, speed and time taken. find out bridge length.
speed= train length + bridge length
----------------------------
time taken to cross
we know train length, speed and time taken. find out bridge length.
Hari said:
2 decades ago
Super.
Atul said:
1 decade ago
Plz give me trick to solve to this. Bcz compny gives 1 minute /question and question is so lengthy, then how can I mange my time.
Mahes said:
1 decade ago
I have solved this problem in a different way, is this right way to solve?
Speed = 25/2 m/sec
Length of the bridge be x m.
Total distance = Speed * Time
x + 130 = 30 * 25/2
x + 130 = 375
x = 245 m
Is the above method to solve this problem right?
Please explain.
Speed = 25/2 m/sec
Length of the bridge be x m.
Total distance = Speed * Time
x + 130 = 30 * 25/2
x + 130 = 375
x = 245 m
Is the above method to solve this problem right?
Please explain.
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.
Gkvinodh said:
1 decade ago
How the equation (130 + x) /2 = 25/2 comes ?
Mubeen said:
1 decade ago
@Coolburn
Yep... Quite simple and understandable.
Yep... Quite simple and understandable.
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.
Ruby said:
1 decade ago
Hey frnd........i sol dis prob in diff way..
length of train=130m
speed=45km/hr
time=30sec
l=s*t
l=(45*5/18)*30
l=(25/2)*30
l=375
length of bridge=l-length of train
x=375-130
x=245m...........
is dis is rite method????????
length of train=130m
speed=45km/hr
time=30sec
l=s*t
l=(45*5/18)*30
l=(25/2)*30
l=375
length of bridge=l-length of train
x=375-130
x=245m...........
is dis is rite method????????
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers