Official Guide Explanation:
Data Sufficiency #84

Background

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Solution and Metadata

Question: 84
Page: 159
Difficulty: 4 (Moderately Easy)
Category 1: Algebra > Linear Equations-Two Unk >
Category 2: Word Problems > Other >

Explanation: We're looking for the value of the expression 25p + 30n, where p is the weight of one photograph and n is the weight of one negative.

Statement (1) gives us one equation with the variables p and n (p = 3n), but no actual weight amount, so it is insufficient. Statement (2) offers another equation with the variables p and n (p + 2n = (1/3)) but nothing we can directly translate into the value of 25p + 30n.

Taken together, the statements are sufficient. We have two variables and two distinct linear equations. With those, we can find the values of p and n and plug them into the initial expression. Choice (C) is correct.

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