Question:
Two trains 140 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time (in seconds) which they take to cross each other, is:
[A].9
9.6
10
10.8
Two trains 140 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time (in seconds) which they take to cross each other, is:
[A].
[B].
[C].
[D].
Answer: Option D
Explanation:
| Relative speed = (60 + 40) km/hr = | 100 x | 5 | m/sec | = | 250 | m/sec. | ||
| 18 | 9 |
Distance covered in crossing each other = (140 + 160) m = 300 m.
| Required time = | 300 x | 9 | sec | = | 54 | sec = 10.8 sec. | |
| 250 | 5 |