issb mathematics MCQ #699

If average of 5 numbers is 18 and four sum to 70, fifth?

issb mathematics MCQ #699

  1. Question 1

    Q1. If average of 5 numbers is 18 and four sum to 70, fifth?

    • A) 18
    • B) 19
    • C) 20
    • D) 21

    Answer: 20

    Explanation: Total 90 minus 70 gives fifth number 20. Work each step carefully; ISSB math rewards accuracy under time pressure.