What is the average (arithmetic mean) of a, b, c, d, e, and f with a < b < c < d < e < f ?

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What is the average (arithmetic mean) of a, b, c, d, e, and f with a < b < c < d < e < f ?

(1) The average of d, e, and f is 11.
(2) The value of a is 5 and b + c + d + e + f = 51.


OA B

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BTGmoderatorDC wrote:
Fri Mar 11, 2022 7:56 pm
What is the average (arithmetic mean) of a, b, c, d, e, and f with a < b < c < d < e < f ?

(1) The average of d, e, and f is 11.
(2) The value of a is 5 and b + c + d + e + f = 51.


OA B

Source: GMAT Prep
Target question: What is the average (arithmetic mean) of a, b, c, d, e, and f

Statement 1: The average of d, e, and f is 11.
We can take this information and write: (d + e + f)/3 = 11, which means d + e + f = 33.
However, since we have no information about the value of a, b and c, there's no way to find the average of a, b, c, d, e, and f
Since we can't answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: The value of a is 5 and b + c + d + e + f = 51.
Average of the 6 values = (a + b + c + d + e + f)/6
Substitute given values: = (5 +51)/6
Simplify: = 56/6
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer: B

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Brent
Brent Hanneson - Creator of GMATPrepNow.com
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