Aptitude - Problems on Trains - Discussion

Discussion Forum : Problems on Trains - General Questions (Q.No. 2)
2.
A train 125 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 seconds. The speed of the train is:
45 km/hr
50 km/hr
54 km/hr
55 km/hr
Answer: Option
Explanation:

Speed of the train relative to man = 125 m/sec
10

   = 25 m/sec.
2

   = 25 x 18 km/hr
2 5

   = 45 km/hr.

Let the speed of the train be x km/hr. Then, relative speed = (x - 5) km/hr.

x - 5 = 45         x = 50 km/hr.

Discussion:
493 comments Page 50 of 50.

Md shahrukh Ansari said:   1 month ago
Good Explanation. Thanks a lot.
(1)

DHANASURIYA M G said:   4 weeks ago
Convert the man's speed to meters per second: 5km/hr = 5 × 10003600 ≈ 1.39m/s.

The train covers its length (125 m) in 10 seconds, so its speed relative to the man is 125m/10s = 12.5m/s.
Therefore, the speed of the train is;
12.5 m/s + 1.39 m/s ≈ 13.89 m/s.
which is converted to 50 km/hr.
(6)

Ravi prasad said:   3 weeks ago
Relative speed = x - 5.

Formula:

Relative speed = Distance/time.
(x-5) 5/18 = 125/10.
X = (12. 5x18/5) + 5.
= 45 + 5 = 50km/hr.
(5)


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