Classification – Odd one out (perfect square among non-squares) Among the following integers, three are not perfect squares while exactly one is a perfect square. Identify the perfect square and mark it as the odd one out.

Introduction / Context:
Odd-one-out items often target quick recognition of perfect squares. Being able to spot classic squares like 29^2 = 841 lets you classify efficiently without lengthy computation.

Given Data / Assumptions:

• Candidates: 626, 841, 962, 1090
• Goal: find the single perfect square
• All values are base-10 integers with no extra conditions

Concept / Approach:
Recall common squares around 30^2 = 900. Specifically, 29^2 = 841 and 31^2 = 961. Compare each option to see whether it equals k^2 for some integer k. If a number sits strictly between two consecutive squares, it is not a perfect square.

Step-by-Step Solution:
841 = 29^2 → perfect square.626 lies between 25^2 = 625 and 26^2 = 676 → not a square.962 lies between 31^2 = 961 and 32^2 = 1024 → not a square.1090 lies between 33^2 = 1089 and 34^2 = 1156 → not a square.

Verification / Alternative check:
Square-root estimates: sqrt(841) = 29 exactly; sqrt(626) ≈ 25.0+, sqrt(962) ≈ 31.0+, sqrt(1090) ≈ 33.0+, none integral. Only 841 matches an integer root, confirming it as the unique square.

Why Other Options Are Wrong:

• 626: Not equal to any k^2.
• 962: Not equal to any k^2.
• 1090: Not equal to any k^2.
• None of these: There is one clear square (841).

Common Pitfalls:
Assuming that being close to a square (e.g., 626 near 625) implies squareness. Only exact equality to k^2 qualifies.

Final Answer:
841