Two trains 140 m and 160 m long run at the speed of 60 km/hr and 40 k…

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:

Accepted Answer

Option D. 10.8. Answer & Solution Answer: Option D Solution: & Relative\, speed = ( 60 + 40 )\, km/hr & = 100 × 518 \, m/sec & = 2509 \, m/sec. & Distance\, covered\, in\, crossing\, each\, other & = ( 140 + 160 )m = 300\,m & Required\, time & = 300 × 9250 \, sec & = 545\, sec & = 10.8\, sec