issb mathematics MCQ #809

A alone 18 days, B alone 36 days. Together?

issb mathematics MCQ #809

  1. Question 1

    Q1. A alone 18 days, B alone 36 days. Together?

    • A) 10 days
    • B) 11 days
    • C) 12 days
    • D) 13 days

    Answer: 12 days

    Explanation: Rates 1/18 plus 1/36 equals 1/12 so 12 days. Work each step carefully; ISSB math rewards accuracy under time pressure.