The sum of three consecutive natural numbers each divisible by 3 is 72. What…

2025

The sum of three consecutive natural numbers each divisible by 3 is 72. What is the largest among them?

  1. A.

    21

  2. B.

    24

  3. C.

    25

  4. D.

    27

Attempted by 30 students.

Show answer & explanation

Correct answer: D

Solution: Interpret the phrase "three consecutive natural numbers each divisible by 3" as three consecutive multiples of 3.

  1. Let the three consecutive multiples of 3 be 3k, 3k+3, and 3k+6.

  2. Their sum is 3k + (3k+3) + (3k+6) = 9k + 9, and this equals 72.

  3. Solve 9k + 9 = 72 → 9k = 63 → k = 7.

  4. The numbers are 3·7 = 21, 3·8 = 24, and 3·9 = 27. The largest is 27.

  5. Quick check: 21 + 24 + 27 = 72, so the answer is correct.

Explore the full course: Deloitte Nla