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.
-
A72572
-
B35453
-
C78378
-
D46246
-
ENone of these
Answer
Correct Answer: 35453
Explanation
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