Question: What is the average (arithmetic mean) annual salary of the 6 employees of a toy company?
(1) If the 6 annual salaries were ordered from least to greatest, each annual salary would be $6,300 greater than the preceding annual salary.
(2) The range of the 6 annual salaries is $31,500.
“What is the average (arithmetic mean) annual salary of the 6 employees”- is a topic of the GMAT Quantitative reasoning section of GMAT. This question has been taken from the book "GMAT Official Guide Quantitative Review 2021". GMAT Quant section consists of a total of 31 questions. GMAT Data Sufficiency questions consist of a problem statement followed by two factual statements. GMAT data sufficiency comprises 15 questions which are two-fifths of the total 31 GMAT quant questions.
Solution and Explanation:
Approach Solution 1:
(1) If the 6 annual salaries were ordered from least to greatest, each annual salary would be $6,300 greater than the preceding annual salary.
x, x + 6300, x + 2 * 6300, x + 3 * 6300, x + 4* 6300, x + 5 * 6300
Avg = ( x + ( x + 5 * 6300 )) / 2
= ( 2x + 5 * 6300 ) / 2
No information about x
Insufficient
(2) The range of the 6 annual salaries is $31,500.
|No information about individual salary
Insufficient
Combining both :
No new information, St 2) can be derived from St 1) itself
Insufficient
Correct Answer: E
Approach Solution 2:
The average = Sum of salaries/6
Let first salary be x
The next salary will be x + 6,300 and so it goes to the 6th salary that equals x + 6,300*5
We have one variable that we don't know
Insufficient.
Statement 2)
Tells us the range X6 - X1 = 31,500
So we don't have anything specific about the salaries. Insufficient.
Now combine
The range is basically X6 - X1 = x + 6,300 *5 - x = 31,500
Basically tautology.
We don't know the value of x.
Insufficient.
Correct Answer: E
Approach Solution 3:
We don't know individual values. So insufficient.
2. We know only the ranges. Value can be anything. So insufficient
1+2 salaries are 0,6300,12600,18900,25200,31500
6300,12600,18900,25200,31500,37800
So any values possible. So insufficient
Correct Answer: E
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