Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 20)
20.
A train moves past a telegraph post and a bridge 264 m long in 8 seconds and 20 seconds respectively. What is the speed of the train?
Answer: Option
Explanation:
Let the length of the train be x metres and its speed by y m/sec.
| Then, | x | = 8  x = 8y |
| y |
| Now, | x + 264 | = y |
| 20 |
8y + 264 = 20y
y = 22.
 Speed = 22 m/sec = |
 |
22 x | 18 |  |
km/hr = 79.2 km/hr. |
| 5 |
Discussion:
46 comments Page 1 of 5.
Ravibhai said:
2 years ago
Simple:
Time = Distance/Speed.
Speed = Distance/Time.
= 264/(20-8)×5/18.
= 79.2km/h.
Time = Distance/Speed.
Speed = Distance/Time.
= 264/(20-8)×5/18.
= 79.2km/h.
(18)
Vishnu said:
3 years ago
D = 264m,
T1 = 8 s,
T2 = 20s,
T = 20-8,
T = 12sec,
S = D/T.
S= 264/12,
S= 22 m/s,
S * 5/18 = 22.
S = 22 * 18/5.
S = 79.2 km/hr.
T1 = 8 s,
T2 = 20s,
T = 20-8,
T = 12sec,
S = D/T.
S= 264/12,
S= 22 m/s,
S * 5/18 = 22.
S = 22 * 18/5.
S = 79.2 km/hr.
(24)
PRIYADARSHI PRATTYULYA KUMAR BHATTA said:
4 years ago
Simply the solution is;
12sec = 264
1sec = 264/12 = 22.
i.e. speed is 22 m / sec.
So we convert it into km/hr.
That is 22*18/5 = 79.2 km/hr.
12sec = 264
1sec = 264/12 = 22.
i.e. speed is 22 m / sec.
So we convert it into km/hr.
That is 22*18/5 = 79.2 km/hr.
(19)
Vasu said:
5 years ago
Thank you @Randhir.
Debashis said:
6 years ago
****Simple technique************
let's length of train = x.
Sp. of train = x/8.
Mathematically, (x+264)/20 = x/8.
or, x=176 m.
Now, speed of train = (176/8)*(18/5) = 79.2 km/hr.
let's length of train = x.
Sp. of train = x/8.
Mathematically, (x+264)/20 = x/8.
or, x=176 m.
Now, speed of train = (176/8)*(18/5) = 79.2 km/hr.
(7)
Govindraj said:
6 years ago
Hi all,
22 m/s = 22*1000/3600 km/hr = 6.1 km/hr.
Let me know if I am wrong.
22 m/s = 22*1000/3600 km/hr = 6.1 km/hr.
Let me know if I am wrong.
(2)
Prashant said:
6 years ago
Thanks @Randhir.
Laxman biradar said:
7 years ago
Nice explanation @Gaurav Reddy.
Shambhu said:
7 years ago
Hi, I can't understand please explain me.
Aishuy said:
7 years ago
How will make 22*18/5? Please explain this step.
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