Home » Aptitude » Speed, Time and Distance » Question
  1. Two trains, of same length, are running on parallel tracks in the same direction with speed 60 km/hour and 90 km/hour respectively. The latter completely crosses the former in 30 seconds. The length of each train (in metres) is
    1. 125
    2. 150
    3. 100
    4. 115
Correct Option: A

When two trains cross each other, they cover distance equal to the sum of their length with relative speed.
Let length of each train = x metre
Relative speed = 90 – 60
= 30 kmph

=
30 × 5
m/sec.
18

=
25
m/sec.
3

∴ 
2x
= 30
25
3

⇒  2x =
30 × 25
3

⇒  2x = 250
⇒  x = 125 metres


Your comments will be displayed only after manual approval.