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 4 of 26.
Draco said:
6 months ago
So the train must go faster than the man to pass him.
S = D/T.
Meters to km = 18/5,
s = d/t,
d = 125 x 18/5 = 450.
t = 10.
s = 450/10 = 45.
The speed we calculate (45 km/hr) is the extra speed the train has compared to the man.
45 + 5 = 50km/hr.
S = D/T.
Meters to km = 18/5,
s = d/t,
d = 125 x 18/5 = 450.
t = 10.
s = 450/10 = 45.
The speed we calculate (45 km/hr) is the extra speed the train has compared to the man.
45 + 5 = 50km/hr.
(4)
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)
Charan singh said:
4 months ago
2 years ago.
Length of train = 130m.
Length of bridge = ?.
1hr = 3600sec.
= 3600/30.
= 120.
1km = 1000m.
= 45000/120.
= 375m.
The length of the train is less in total.
375-130 = 245.
Length of train = 130m.
Length of bridge = ?.
1hr = 3600sec.
= 3600/30.
= 120.
1km = 1000m.
= 45000/120.
= 375m.
The length of the train is less in total.
375-130 = 245.
(3)
Jahnavi said:
3 weeks ago
Given:
Train length = 130 m
Speed = 45 km/hr
Time = 30 sec
Bridge length = ?
Step 1:
Convert 45 km/hr to m/s
45× 5/18.
Then,
45 * 5/18 = 12.5 m/s.
Step 2:
Distance covered in 30 sec.
Distance = Speed × Time.
= 12.5 × 30,
= 375 m.
Step 3:
Distance = Train length + Bridge length.
375 = 130 + Bridge length.
Bridge length = 375 − 130.
= 245 m.
Train length = 130 m
Speed = 45 km/hr
Time = 30 sec
Bridge length = ?
Step 1:
Convert 45 km/hr to m/s
45× 5/18.
Then,
45 * 5/18 = 12.5 m/s.
Step 2:
Distance covered in 30 sec.
Distance = Speed × Time.
= 12.5 × 30,
= 375 m.
Step 3:
Distance = Train length + Bridge length.
375 = 130 + Bridge length.
Bridge length = 375 − 130.
= 245 m.
(3)
Kavya said:
6 years ago
D= S * T.
D = 45 * 5/18 * 30 = 375m,
375-130=245m.
D = 45 * 5/18 * 30 = 375m,
375-130=245m.
(2)
Sanilam Guha said:
5 years ago
(0.130+x) = (45 * 30)/3600.
If assume x is bridge length;
OR, 0.130 + x = 0.375.
OR, X = 0.375 - 0.130.
OR, X = 0.245 KM OR 245 M.
Am I right?
If assume x is bridge length;
OR, 0.130 + x = 0.375.
OR, X = 0.375 - 0.130.
OR, X = 0.245 KM OR 245 M.
Am I right?
(2)
Arup Kumar subudhi said:
5 years ago
Train Speed is 45 km/sec = (45*5)/18 = 25/2 m/s.
= (25*15)/(2*15) m/s,
= 375/30 m/s.
375 m in 30 sec, so bridge length is = 375 - 130 = 245m.
= (25*15)/(2*15) m/s,
= 375/30 m/s.
375 m in 30 sec, so bridge length is = 375 - 130 = 245m.
(2)
Nusrat fathima said:
2 decades 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 help.
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 help.
(1)
Coolburn said:
2 decades ago
Hi, I had my own solustion on that
45 km/hr
1km = 1000m
1hr = 3600 sec
45 km/hr convert to metter
=45000 m
=3600 sec.
45000/3600
=12.5
Since 30 sec can cross the bridge
=12.5*30
=375-130
=245m
45 km/hr
1km = 1000m
1hr = 3600 sec
45 km/hr convert to metter
=45000 m
=3600 sec.
45000/3600
=12.5
Since 30 sec can cross the bridge
=12.5*30
=375-130
=245m
(1)
Jagabandhu patra said:
1 decade ago
(45000/3600*30)-130 = 245.
(1)
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