Number series – find the wrong term (identify the outlier). Sequence: 25, 36, 49, 81, 121, 169, 225

Introduction / Context:
This series contains perfect squares. The task is to identify which square does not belong to the intended pattern once the underlying rule is recognized.

Given Data / Assumptions:

• Squares listed: 25, 36, 49, 81, 121, 169, 225
• Only one term is wrong with respect to the intended sequence logic.

Concept / Approach:
Note that 25 = 5^2, 49 = 7^2, 81 = 9^2, 121 = 11^2, 169 = 13^2, 225 = 15^2. These are consecutive odd squares starting at 5^2, except one even square appears in the list.

Step-by-Step Solution:

Verification / Alternative check:
Remove 36 and the remaining sequence consists entirely of odd squares in ascending order. No other term violates that rule.

Why Other Options Are Wrong:

• 49, 121, 169: Each is a square of an odd integer and thus fits the intended pattern.

Common Pitfalls:
Assuming the series is simply all consecutive squares. The presence of 36 can mislead; look for a deeper consistency such as only odd squares.

Final Answer:
36