Data sufficiency: not enough — Aptitude Question
Data sufficiency: not enough: Question: What is the value of x? Statement I: x is an even number. Answer and worked solution on CodeKairo.
- Topic: Mathematical Reasoning
- Section: Logical Reasoning
- Difficulty: Medium
- Time target: 90 seconds
Question
Question: What is the value of x?
Statement I: x is an even number. Statement II: x is greater than 4 and less than 10.
Which statements are sufficient?
Options
- I alone is sufficient
- II alone is sufficient
- Both together are sufficient
- Even both together are not sufficient
Show the answer and the worked solution
Correct answer: D. Even both together are not sufficient
Worked solution
- I alone: infinitely many even numbers — not sufficient.
- II alone: 5, 6, 7, 8 or 9 — not sufficient.
- Together: x could be 6 or 8, so the value is still not fixed.
- Even both together are not sufficient.
Answer: Even both together are not sufficient.
The idea
Sufficiency needs a unique answer. If two values survive both statements, the data is insufficient however much it narrows things.
Shortcut. Look for two values that pass both statements: 6 and 8 are both even and lie between 4 and 10. Two survivors mean insufficient — nothing more to check.
Common trap. "Both together are sufficient" — combining the clues, landing on 6 as the first even number above 4 and missing that 8 fits equally well.