Intern
Joined: 27 Nov 2014
Posts: 27
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Location: India
Concentration: International Business, General Management
GMAT 1: 360 Q27 V14
GMAT 2: 430 Q30 V20
GMAT 3: 480 Q36 V20
GPA: 3.78
WE:Engineering (Transportation)
Re: What is the average of x and y? (1) 2x + 3y = 12 (2) x and y are
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09 Mar 2024, 21:38
What is the average of x and y?
(1) 2x + 3y = 12
(2) x and y are positive integers.
So we need to find the average of x and y (x+y/2), but here from the question stem we don't know if x & y are integers or fractions or decimals.
From St 1. 2x+3y=12 put x=3 and y=2 => satisfies the equations. we can get an av. (2.5)
one more possibility is, putting x=0 and y=4 => satisfies the equations. we will get a different av. value. (2)
this is insufficient.. We can also check fraction values by putting x=11/2 and y= 1/3 => satisfies the equations. we will get a different av. value.
St 2. is not of any use as a stand alone statement, but it is just giving us a vital info.
this is insufficient..
combing St. 1 & 2, discard are fractions and decimals values and stick with integers only.
only x=3 and y=2 will answer the main stem question.
Discard x=0 and y=4 as 0 is neither positive nor negative but is considered even in GMAT.
Therefore, answer is C.
Hope it is clear now.
Also, in such type of questions, directly start from statement 2 and save yourself some time and then we can check different combinations of st 1 and only one condition will get satisfied.