Aptitude - Problems on Trains - Discussion

Discussion Forum : Problems on Trains - General Questions (Q.No. 1)
1.
A train running at the speed of 60 km/hr crosses a pole in 9 seconds. What is the length of the train?
120 metres
180 metres
324 metres
150 metres
Answer: Option
Explanation:

Speed = 60 x 5 m/sec = 50 m/sec.
18 3

Length of the train = (Speed x Time).

Length of the train = 50 x 9 m = 150 m.
3

Discussion:
584 comments Page 58 of 59.

Shraddha Jadhav said:   3 months ago
150 is the correct answer.
(5)

Rohit Chouhan said:   3 months ago
First we converted into m/s to speed.

So length = speed *time.
So, length =50 * 3 = 150.
(11)

Naveen said:   3 months ago
Kilometers to meters: There are 1000 meters in 1 kilometer.

Hours to seconds: There are 60 minutes in 1 hour, and 60 seconds in 1 minute, so there are 60×60=3600 seconds in 1 hour.

So, to convert a speed from km/hr to m/sec, you multiply by 3600 seconds1000 meters​.

Now, let's simplify that fraction:
36001000 ​= 3610 ​= 185​.
(10)

Sneha said:   3 months ago
How did you calculate 5/18? Please explain to me.
(40)

Madhusudan Jena said:   2 months ago
Given Time = 9 sec,
Covert Speed km/hr to m/sec.
1 km = 1000m,
1 hr = 60 min,
1 min = 60 sec.
60 min=(60 * 60) sec = 3600 sec.
So, 1 hr = 3600 sec.
1 hr = 3600 sec.

1 km/hr = 1km/1hr = 1000 m/3600 sec = 10/36 m/s = 5/18 m/s,
Speed = 60 km/hr = 60 * 5/18 m/s,
Speed = Distance/Time.
So, the Length of the train = Speed * Time
= 60 * 5/18*9
= 150m.
(68)

Kopila said:   1 month ago
@All.

The answer here calculated is the distance of the train travelled in 9 seconds right, then how can you claim it as the length if the train?
(6)

Ruchita said:   1 month ago
Firstly, you need to check what's given in the question.
So, Now.
THe Time given in seconds.
Distance needed in meters.
So, convert km/hr to m/sec.
1km = 1000m
1hr = 3600sec.
1km/hr = 1000/3600 = 5/18(m/sec).
speed = (60 *5/18) = 50 /3(m/sec).
At last,
The Length = Speed * Time = (50/3 * 9) = 150meters.
(149)

Kamalesh Kamalesh said:   1 month ago
Agree, 150 is the correct answer.
(7)

Gunjan kumari said:   1 month ago
Option D is the right answer.
(6)

Kasthuri said:   1 month ago
How 5/18 came? Please explain to me.
(66)


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