Answer: 25 m.
- A 15 s
- B 20 s
- C 25 m
- D 30 s
Correct answer: C. 25 m
Explanation: Speed = 200/10 = 20 m/s. To pass platform: total distance = 200+300 = 500 m. Time = 500/20 = 25 s.

Projectiles at equal speed: range is maximum at 45°, and complementary angles (30° and 60°) share the same range. Image: Cmglee, CC BY-SA 3.0, via Wikimedia Commons.
Concept context
Vectors, projectile motion, uniform circular motion, and relative velocity - the foundation of 2D kinematics for NEET and JEE.