Question

Difficulty: EasyQuestion Stem Simplification and Target Rephrasing

For any non-zero real numbers xx and yy, the Data Sufficiency target question 'Is xy>0\frac{x}{y} > 0?' is algebraically equivalent to the rephrased target question 'Do xx and yy have the same sign?'

Answer: Answer

Answer

True. The target question simplifies directly to asking whether xx and yy share the same sign.
The target question asks if the ratio xy\frac{x}{y} is positive. In arithmetic, the quotient of two real numbers is positive if and only if both numbers have the same sign (both positive or both negative). Thus, rephrasing the target to 'Do xx and yy have the same sign?' is a completely equivalent simplification.

Step-by-Step Solution

1
Analyze the condition for a fraction to be positive
For xy>0\frac{x}{y} > 0, either (x>0x > 0 and y>0y > 0) or (x<0x < 0 and y<0y < 0).
Dividing two numbers with identical signs yields a positive quotient, while dividing numbers with opposite signs yields a negative quotient.
2
Compare the condition to the proposed rephrased question
The condition 'both positive or both negative' is the definition of xx and yy having the same sign.
Rephrasing a Data Sufficiency stem requires finding a target condition that is true under the exact same conditions as the original question.

Key Concept

Question Stem Rephrasing for Quotient Inequalities
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