Classification – Odd one out (numeric pair rule) Each option is a pair a–b. Exactly one pair satisfies b = 2a. Identify the pair that follows doubling; it is the odd one out with respect to the others.

Introduction / Context:
Pair-classification items often hide a simple arithmetic mapping from the first member to the second. Here we test for the doubling rule b = 2a. The skill is to check each option consistently and spot the single conforming (or non-conforming) case.

Given Data / Assumptions:

• Pairs: 12–28, 14–82, 23–64, 36–72
• We examine whether b equals 2a.

Concept / Approach:
Compute 2a and compare to b in each pair. If exactly one pair matches, that pair is the odd one out relative to the rest (which do not match).

Step-by-Step Solution:
For 12–28: 2 * 12 = 24 ≠ 28 → no.For 14–82: 2 * 14 = 28 ≠ 82 → no.For 23–64: 2 * 23 = 46 ≠ 64 → no.For 36–72: 2 * 36 = 72 → yes (unique).

Verification / Alternative check:
If you try other plausible mappings (sum of digits, product, etc.), none yields a unique consistent rule across three choices. The clean doubling property isolates only 36–72.

Why Other Options Are Wrong:

• 12–28 → not double.
• 14–82 → not double.
• 23–64 → not double.
• None of these → one pair cleanly follows doubling (36–72).

Common Pitfalls:
Overfitting a complicated mapping to force matches on multiple pairs. The test favors a simple, uniquely identifying rule.

Final Answer:
36-72