Question

Difficulty: MediumStatement Independence Evaluation and Statement Combination

In a GMAT Data Sufficiency question asking for the unique value of a variable xx, if Statement (1) alone limits the possible values of xx to the set {2,5}\{2, 5\} and Statement (2) alone limits the possible values of xx to the set {5,8}\{5, 8\}, then the two statements combined are sufficient to answer the question.

Answer: Answer

Answer

True. Combining two consistent Data Sufficiency statements yields a solution set equal to the intersection of their individual solution sets. The intersection of {2,5}\{2, 5\} and {5,8}\{5, 8\} is {5}\{5\}, which uniquely identifies xx and is therefore sufficient.
The statement is true because taking the intersection of the two solution sets {2,5}\{2, 5\} and {5,8}\{5, 8\} leaves only the single value x=5x = 5, satisfying the GMAT Data Sufficiency requirement for a unique value.

Step-by-Step Solution

1
Evaluate Statement (1) alone
Statement (1) yields x{2,5}x \in \{2, 5\}, which contains two possible values and is insufficient on its own.
A Value Data Sufficiency question requires a single unique numerical value for sufficiency.
2
Evaluate Statement (2) alone independently
Statement (2) yields x{5,8}x \in \{5, 8\}, which contains two possible values and is insufficient on its own.
Statement (2) must be evaluated without carrying over any constraints from Statement (1).
3
Combine Statement (1) and Statement (2)
The combined solution set is {2,5}{5,8}={5}\{2, 5\} \cap \{5, 8\} = \{5\}.
Combining statements requires identifying values that satisfy both statements simultaneously.
4
Determine sufficiency of the combined solution set
Since x=5x = 5 is the only value in the combined set, the statements together provide a single unique answer.
A single unique result satisfies the criterion for Data Sufficiency.

Key Concept

Statement Combination and Solution Set Intersection
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