A walks 4 km/h, B runs 8 km/h. B catches A who had 2 km head start in?
Q1. A walks 4 km/h, B runs 8 km/h. B catches A who had 2 km head start in?
Answer: 0.5 h
Explanation: Relative speed 4 km/h closes 2 km gap in 0.5 hours. Work each step carefully; ISSB math rewards accuracy under time pressure.