Two trains, each 100 m long, moving in opposite directions, cross each other in 8 seconds. If one is moving twice as fast the other, then the speed of the faster train is:
Explanation
Let the speed of the slower train be x m/sec.
Then, speed of the faster train = 2x m/sec.
Relative speed = (x + 2x) m/sec = 3x m/sec.
(100 + 100) | = 3x | |
8 |
24x = 200
x = | 25 | . |
3 |
So, speed of the faster train = | 50 | m/sec |
3 |
= | 50 | x | 18 | km/hr | |
3 | 5 |
= 60 km/hr.