Find the next two numbers that continue the alternating pattern. Sequence: 8, 12, 9, 13, 10, 14, 11, ____ , ____

Difficulty: Easy

Correct Answer: 15 12

Explanation:

Introduction / Context:Here two simple progressions are interleaved: one affects odd-position terms and the other affects even-position terms. Recognizing the interleave is the key step.

Given Data / Assumptions:

  • Series: 8, 12, 9, 13, 10, 14, 11, …
  • We must supply the next two terms.

Concept / Approach:Separate the series into odd and even indices; examine each subsequence independently.

Step-by-Step Solution:

Odd positions: 1st=8, 3rd=9, 5th=10, 7th=11 → increases by +1.Even positions: 2nd=12, 4th=13, 6th=14 → increases by +1.After the 7th term (11, odd), the 8th term is the next even subsequence value: 14 + 1 = 15.The 9th term resumes the odd subsequence: 11 + 1 = 12.

Verification / Alternative check:Write the two subsequences explicitly: odd = 8, 9, 10, 11, 12, … and even = 12, 13, 14, 15, … Interleaving them gives …, 11, 15, 12 which matches the derived pair.

Why Other Options Are Wrong:

  • 14 11: Reverses the order and repeats existing values.
  • 8 15 / 8 5: Return to earlier numbers breaks monotonic +1 growth.
  • 15 19: Even term 15 is fine, but 19 ignores the +1 odd-step.

Common Pitfalls:Continuing only one subsequence or mixing their orders. Always track position (odd/even) before extending.

Final Answer:15 12

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