Official Guide Explanation:
Data Sufficiency #60




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Solution and Metadata

Question: 60
Page: 278
Difficulty: 4 (Moderately Easy)
Category 1: Algebra > Linear Equations-Two Unk >
Category 2: Arithmetic > Ratio and Proportion >

Explanation: The question gives one linear equation with two variables. To find the value of one of the variables, you'll need another linear equation.

Statement (1) is just that: you can substitute the value of s into the initial equation and solve for n, so (1) is sufficient. (2) is also sufficient: it's not so direct, but it is a linear equation with the same two variables, so, combined with the initial equation, it is enough information to solve for n. Choice (D) is correct.

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