issb mathematics MCQ #683

Pipe A fills 6 h, B empties 12 h. Net fill time?

issb mathematics MCQ #683

  1. Question 1

    Q1. Pipe A fills 6 h, B empties 12 h. Net fill time?

    • A) 10 h
    • B) 11 h
    • C) 12 h
    • D) 14 h

    Answer: 12 h

    Explanation: Net rate 1/6 minus 1/12 equals 1/12 so 12 hours. Work each step carefully; ISSB math rewards accuracy under time pressure.