Extend the alternating-difference series by two terms. Sequence: 36, 31, 29, 24, 22, 17, 15, ____ , ____

Difficulty: Easy

Correct Answer: 10 8

Explanation:


Introduction / Context:
Many quantitative series alternate between two fixed negative differences. Identifying the cycle length and values lets you project future terms confidently.


Given Data / Assumptions:

  • Series: 36, 31, 29, 24, 22, 17, 15
  • Find the next two terms.


Concept / Approach:
Calculate consecutive differences and look for an A-B-A-B pattern.


Step-by-Step Solution:

36→31: -531→29: -229→24: -524→22: -222→17: -517→15: -2Cycle is (-5, -2) repeating.Next after 15: -5 → 15 - 5 = 10.Then: -2 → 10 - 2 = 8.


Verification / Alternative check:
The derived pair 10, 8 maintains the exact alternating-difference rhythm.


Why Other Options Are Wrong:

  • 13 11 / 12 7 / 13 8 / 10 5: Each mismatches the -5 then -2 cycle after 15.


Common Pitfalls:
Assuming a constant difference or reversing the order of the alternating differences. Always write the last few steps explicitly.


Final Answer:
10 8

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