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:
200 m
225 m
245 m
250 m
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.

Anonymous said:   1 year ago
I am not getting this answer. Anyone, please help me by explaining it.
(8)

Draco said:   9 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.
(4)

Vanitha peddireddy said:   7 months ago
Train = 130.
Bridge = x.
Distance = 45,
1000/3600 = 5/18.
45 * 5/18 * 30 = 375,
375 - 130 = 245 = C.
(4)

Charan singh said:   7 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.
(4)

Kavya said:   7 years ago
D= S * T.

D = 45 * 5/18 * 30 = 375m,
375-130=245m.
(2)

Sanilam Guha said:   6 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?
(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.
(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.
(1)

Mahes 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 explain.
(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
(1)


Post your comments here:

Your comments will be displayed after verification.