Official Guide Explanation:
Data Sufficiency #D46




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Solution and Metadata

Question: D46
Page: 25
Difficulty: 5 (Moderate)
Category 1: Arithmetic > Percents > other
Category 2: Arithmetic > Descriptive Statistics > Average

Explanation: The information given includes the average of the 10 employees' salaries last year, from which we could determine the total salary paid to the 10 employees. To find the average salary this year, we need to know how much each of the employees' salaries changed.

Statement (1) is insufficient. We don't know what happened with the other 2 salaries, and we don't know how much of the total those 8 salaries made up.

Statement (2) is also insufficient. We don't know about the other 8 salaries, and we don't know what fraction of the total those 2 salaries represented.

Taken together, the statements are still insufficient. While we know that 8 salaries increased by 15% and 2 salaries stayed the same, we don't know how much money is represented by the 8 salaries and the 2 salaries. The total salary is about $430,000; if the 2 salaries that stayed the same totaled $30,000, the resulting salary this year is much greater than if the two salaries that stayed the same totaled $130,000. Choice (E) is correct.

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