Two trains start simultaneously from two stations Howrah and Delhi, respectively towards each other on the same track. The distance between the two stations is 560 km and the speeds of trains are 30 kmph and 40 kmph. Simultaneously with the trains, a sparrow sitting on the top of one of the train starts towards the other and reverses its direction on reaching the other train and so on. If the speed of sparrow is 80 kmph then the distance that the sparrow lies before being crushed between the train is :

A. 70 km

B. 560 km

C. 640 km

D. 650 km

E. None of these

Answer: Option C

Solution(By Examveda Team)

Relative speed of the trains = 40 + 30 = 70 kmph.
Time taken by trains to collide,
= $$\frac{{560}}{{70}}$$
= 8h.
In 8h sparrow will cover,
= 8 × 80
= 640 km.