What is the average (arithmetic mean) of x and y?
(1) The average (arithmetic mean) of (x + 1) and (y - 1) is equal to the average (arithmetic mean) of x and y.
(2) The average (arithmetic mean) of x, y, and -1 is 1.
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of x and y?
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- sanju09
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- sumit.sinha
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what is (x+y) ?sanju09 wrote:What is the average (arithmetic mean) of x and y?
(1) The average (arithmetic mean) of (x + 1) and (y - 1) is equal to the average (arithmetic mean) of x and y.
(2) The average (arithmetic mean) of x, y, and -1 is 1.
[spoiler]Source: https://www.west.net/~stewart/gmat[/spoiler]
(1) (x+1 + y -1)/2 = (x+y)/2
i.e. (x+y)/2 = (x+y)/2
(x+y) could be 0,1,2...and so on anything. INSUFFICIENT
(2) (x+y-1)/3 =1
i.e. x+ y = 4
SUFFICIENT
CORRECT ANSWER (B) IMO.
Cheers,
Sumit
Sumit
- tpr-becky
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I agree - the first statement only tells you what you already know becuase the +1 and -1 cancel each other out.
The second statement gives you another equation from which you can determine the value of x+y which is all you really need tofind their average.
The second statement gives you another equation from which you can determine the value of x+y which is all you really need tofind their average.
Becky
Master GMAT Instructor
The Princeton Review
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Master GMAT Instructor
The Princeton Review
Irvine, CA