What is the next number in the series: 8, 16, 24, 36, 48, ?

2025

What is the next number in the series: 8, 16, 24, 36, 48, ?

  1. A.

    60

  2. B.

    56

  3. C.

    64

  4. D.

    72

Show answer & explanation

Correct answer: C

Concept: This series is built by alternating between two rules for consecutive integers n: an odd step gives n2 − 1, and the following even step gives n2 exactly. The value of n increases by 1 with every term.

  1. n = 3: 32 − 1 = 9 − 1 = 8

  2. n = 4: 42 = 16

  3. n = 5: 52 − 1 = 25 − 1 = 24

  4. n = 6: 62 = 36

  5. n = 7: 72 − 1 = 49 − 1 = 48

  6. n = 8: 82 = 64 → this is the next term

Cross-check: The gaps between the five known terms are 8, 8, 12, 12 — repeating in equal pairs and growing by 4 every two terms. Continuing that pattern, the next gap must also repeat within its pair at 16, giving 48 + 16 = 64 — confirming the same result independently.

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