A freight train left Delhi for Mumbai at an average speed of 40 km/hr. Two hours later, an express train left Delhi for Mumbai, following the freight train on a parallel track at an average speed of 60 km/hr. How far from Delhi would the express train meet the freight train?
Answer & explanation
Answer: (c) 240 km
The freight train has an 80 km lead when the express starts. The express closes the gap at 20 km/h, taking 4 hours, by which time it has run 60 × 4 = 240 km from Delhi.
- Lead of the freight train when the express starts = 40 × 2 = 80 km.
- Relative speed = 60 − 40 = 20 km/h, so time to catch up = 80 ÷ 20 = 4 h.
- Distance of the express from Delhi = 60 × 4 = 240 km.
- Check: the freight train has run 40 × 6 = 240 km in 6 hours.
Remember · Catch-up time = head start ÷ relative speed; then distance = the chaser's speed × that time.
Question and answer: UPSC's official GS Paper II (2017, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·