Two trains, 140 m and 160 m long, run in opposite directions on parallel lines at 60 km/hr and 40 km/hr, respectively. The time it takes them to cross each other in seconds is:
A. 9
B. 9.6
C. 10
D. 10.8
Answer:D
Two trains, 140 m and 160 m long, run in opposite directions on parallel lines at 60 km/hr and 40 km/hr, respectively. The time it takes them to cross each other in seconds is:
A. 9 B. 9.6 C. 10 D. 10.8
Explanation: 100 x 5/18 m/sec = 250/9 m/sec= Relative speed = (60 + 40) km/hr,(140 + 160) m = 300 m is the distance traversed when they cross each other.Time required = 300 x 9/250 sec = 54/5 sec = 10.8 sec