Pipe A fills in 3 h, B fills in 6 h. Both open, fill time?
Q1. Pipe A fills in 3 h, B fills in 6 h. Both open, fill time?
Answer: 2 h
Explanation: Combined rate 1/3 plus 1/6 equals 1/2 so 2 hours. Work each step carefully; ISSB math rewards accuracy under time pressure.