issb mathematics MCQ #811

A and B together 5 days, A alone 15 days. B alone?

issb mathematics MCQ #811

  1. Question 1

    Q1. A and B together 5 days, A alone 15 days. B alone?

    • A) 6 days
    • B) 7 days
    • C) 7.5 days
    • D) 8 days

    Answer: 7.5 days

    Explanation: B rate is 1/5 minus 1/15 equals 2/15 so 7.5 days. Work each step carefully; ISSB math rewards accuracy under time pressure.