# Two trains 160 meter long and 140 m long respectively run at the rate of 77 kmph and 67 kmph respectively in opposite directions on parallel tracks. How long do they take to pass each other?

 [ A ]    4.5 seconds [ B ]    5.5 seconds [ C ]    6.5 seconds [ D ]    7.5 seconds
 Answer : Option D Explanation : time = $160 + 140 \over 77 \times {5 \over 18} + 67 \times {5 \over 18 }$ = $300 \over {5 \over 18} \times 144$ = $300 \over 40$ = 7.5 seconds