Classification – Odd one out (parity: only odd vs evens) Among the following five-digit and four-digit integers, three are even while exactly one is odd. Identify the odd number (by parity) and mark it as the odd one out.

Introduction / Context:
Parity (even/odd) is a rapid classification key. When three values share evenness and one is odd, the parity test immediately yields the outlier with zero arithmetic beyond checking the last digit.

Given Data / Assumptions:

• Set: 72572, 35453, 78378, 46246
• We test parity only.

Concept / Approach:
An integer is even if its last digit is 0, 2, 4, 6, or 8; otherwise it is odd. Scan the last digit of each number and select the single odd element.

Step-by-Step Solution:
72572 → ends with 2 → even.78378 → ends with 8 → even.46246 → ends with 6 → even.35453 → ends with 3 → odd → outlier.

Verification / Alternative check:
Any further divisibility checks are unnecessary; parity alone uniquely identifies 35453 as different from the other three.

Why Other Options Are Wrong:

• 72572: Even; part of the majority class.
• 78378: Even; part of the majority class.
• 46246: Even; part of the majority class.
• None of these: There is exactly one odd number (35453).

Common Pitfalls:
Overcomplicating with prime or 11-divisibility rules when a simpler parity rule suffices and yields a unique choice.

Final Answer:
35453