Number pattern — identify the odd term in the alternating pattern: 5, 16, 6, 16, 7, 16, 9
Aptitude
Odd Man Out and Series
Difficulty: Easy
Choose an option
-
A9
-
B7
-
C6
-
DNone of these
Answer
Correct Answer: 9
Explanation
Introduction / Context:This sequence alternates between a changing number and a fixed number. Detecting the alternating positions (odd/even indices) quickly reveals which entry is inconsistent.
Given Data / Assumptions:
- Sequence: 5, 16, 6, 16, 7, 16, 9
- Positions: 1st, 3rd, 5th, 7th terms are the varying stream; 2nd, 4th, 6th terms are constant.
Concept / Approach:Read terms in two interleaved subsequences: one fixed at 16, the other apparently increasing by 1 each occurrence. Any break in either subsequence marks the odd term.
Step-by-Step Solution:
Fixed subsequence (even positions): 16, 16, 16 — consistent.Varying subsequence (odd positions): 5 → 6 → 7 → expected 8.But the last odd-position term is 9, which skips 8.Therefore, 9 is the odd term.Verification / Alternative check:
Corrected sequence would be 5, 16, 6, 16, 7, 16, 8.Why Other Options Are Wrong:
7 and 6 fit the +1 progression; “None of these” is incorrect because a clear outlier (9) exists.Common Pitfalls:
Treating the series as a single arithmetic progression rather than two interwoven sub-series.Final Answer:9