gs1easy
Two trains leave New Delhi at the same time. One travels north at 60 kmph and the other travels south at 40 kmph. After how many hours will the trains be 150 km apart?
- A.3/2
- B.4/3
- C.3/4
- D.15/2
▶ Answer & Explanation
Correct answer: A. 3/2
The relative speed of two objects moving in opposite directions is the sum of their individual speeds. In this case, the trains are moving north and south, which are opposite directions relative to their starting point. Their combined speed of separation is 60 kmph + 40 kmph = 100 kmph. To cover a distance of 150 km, the time taken would be distance divided by speed, which is 150 km / 100 kmph.
Source: UPSC gs1 2010