Question

Difficulty: Very hardValue vs. Yes/No Data Sufficiency Decision Logic

In a GMAT Data Sufficiency 'Yes/No' question regarding whether a real variable xx is positive, a statement establishing that x24x+3=0x^2 - 4x + 3 = 0 is sufficient, whereas in a 'Value' question asking for the exact numerical value of xx, the exact same statement is insufficient.

Answer: Answer

Answer

The statement is True.
The statement accurately reflects GMAT Data Sufficiency decision rules: a 'Yes/No' question requires only that all possible cases produce a uniform 'Yes' or uniform 'No' answer (which occurs here since both x=1x=1 and x=3x=3 are positive), while a 'Value' question strictly requires a single unique value (which fails here due to having two solutions).

Step-by-Step Solution

1
Analyze the mathematical implications of the given statement.
Solving x24x+3=0x^2 - 4x + 3 = 0 yields (x1)(x3)=0(x-1)(x-3) = 0, so x=1x = 1 or x=3x = 3.
Determine the exact solution set allowed by the statement.
2
Evaluate sufficiency for a 'Yes/No' Data Sufficiency question stem.
Since both x=1x = 1 and x=3x = 3 are strictly greater than 00, the answer to 'Is x>0x > 0?' is unconditionally 'Yes'. Thus, the statement is sufficient.
In 'Yes/No' DS logic, any statement that yields a definitive, consistent 'Yes' (or a definitive, consistent 'No') is sufficient.
3
Evaluate sufficiency for a 'Value' Data Sufficiency question stem.
Since xx can be either 11 or 33, a single unique value for xx cannot be determined. Thus, the statement is insufficient.
In 'Value' DS logic, a statement is sufficient if and only if it leads to exactly one numerical value.
4
Compare the conclusions with the given assertion.
The assertion correctly identifies that the statement is sufficient for 'Yes/No' logic and insufficient for 'Value' logic.
Confirm total alignment between the assertion and GMAT DS decision logic.

Key Concept

Value vs. Yes/No Data Sufficiency Decision Logic
Rate this question