Difficulty: Medium
Correct Answer: 124
Explanation:
Introduction / Context:Structural-factor patterns are common in classification problems. Here, three options equal k * (k+1) * (k+2) for some positive integer k (i.e., product of three consecutive integers). One option does not match this structure. We must identify the mismatch.
Given Data / Assumptions:
Concept / Approach:Test nearby triplets efficiently: for a given target N, find a central cube root to anchor k and check products around that value. Alternatively, check known small products of three consecutive integers.
Step-by-Step Solution:
24 = 2 * 3 * 4 → matches pattern (k = 2).60 = 3 * 4 * 5 = 60 → matches (k = 3).210 = 5 * 6 * 7 = 210 → matches (k = 5).124 → neighbors: 4 * 5 * 6 = 120 and 5 * 6 * 7 = 210 → 124 is not of required form.Verification / Alternative check:Observe that products of three consecutive integers are always divisible by 3 and by 2 (hence even and a multiple of 3). While 124 is even, it is not divisible by 3 (1 + 2 + 4 = 7), which already suggests it cannot be k * (k+1) * (k+2).
Why Other Options Are Wrong:They are correct examples of the pattern and thus not the odd item.
Common Pitfalls:Checking only proximity (e.g., 124 being close to 120) without verifying exact factorization into consecutive integers.
Final Answer:124 does not equal a product of three consecutive integers and is the odd number.
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