Find the odd number out: 331, 482, 551, 263, 383, 242, 111

Introduction / Context:
Some odd-man-out puzzles rely on a distinctive arithmetic property rather than a recursive rule. Here, digit patterns and basic divisibility tests are good first checks to isolate a unique number among peers.

Given Data / Assumptions:

• Numbers: 331, 482, 551, 263, 383, 242, 111.
• We are to find the single term that differs by a clear numeric property from the rest.

Concept / Approach:
Apply divisibility-by-3 test: a number divisible by 3 must have digit-sum divisible by 3. Evaluate each candidate and see whether only one satisfies this condition, making it the “odd man out.”

Step-by-Step Solution:
331 → digit sum 3+3+1 = 7 (not divisible by 3)482 → 4+8+2 = 14 (not divisible by 3)551 → 5+5+1 = 11 (not divisible by 3)263 → 2+6+3 = 11 (not divisible by 3)383 → 3+8+3 = 14 (not divisible by 3)242 → 2+4+2 = 8 (not divisible by 3)111 → 1+1+1 = 3 (divisible by 3)

Verification / Alternative check:
Beyond the divisibility test, 111 also uniquely comprises three identical digits, a secondary distinctive property. No other number in the set shares both features, reinforcing the choice.

Why Other Options Are Wrong:

• 263 / 383 / 242: All fail the divisibility-by-3 test and lack the “all digits equal” feature; they do not stand out uniquely.

Common Pitfalls:

• Forcing a complicated recurrence; in some odd-man-out items, a single clean property (like divisibility by 3) is intended.

Final Answer:
111