The correct answer is A.
Option 1:
=> x=2x+2y => x+2y=0 => x=-2y
Putting the value of x in (2x+y)/(x-2y), we get
=> (-3y)/(-4y) = 3/4 .......... Option 1 sufficient.
Option 2:
=> x=2y+4 => (2x+y)/(x-2y) = (5y+8)/(4) ............... Option 2 insufficient.
Algebra - DS
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(1) x/(x + y) = 2vinni.k wrote:Answer is A
Thanks & Regards
Vinni
x = 2x + 2y
x + 2y = 0 or x = -2y
So, (2x + y)/(x - 2y) = [2(-2y) + y]/[-2y - 2y] = -3y/-4y = 3/4; SUFFICIENT.
(2) x - 2y = 4
x = 4 + 2y
So, (2x + y)/(x - 2y) = [2(4 + 2y) + y]/[(4 + 2y) - 2y] = (5y + 8)/4, which is in terms of y; NOT sufficient.
The correct answer is A.
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What is (2x+y)/(x-2y)?vinni.k wrote:Answer is A
Thanks & Regards
Vinni
An alternate approach:
-- simplify the statements
-- plug different combinations of values into the question stem
Statement 1: x/(x+y) = 2.
First, a bit of algebra:
x = 2x + 2y
x = -2y.
Case 1: y=1, x=-2
(2x+y)/(x-2y) = (2(-2) + 1)/(-2 - 2*1) = -3/-4 = 3/4.
Case 2: y=2, x=-4
(2x+y)/(x-2y) = (2(-4) + 2)/(-4 - 2*2) = -6/-8 = 3/4.
Since the result in each case is 3/4, SUFFICIENT.
Statement 2: x-2y=4.
First a bit of algebra:
x = 2y+4
Case 1: y=1, x=6
(2x+y)/(x-2y) = (2*6 + 1)/(6 - 2*1) = 13/4.
Case 2: y=2, x=8
(2x+y)/(x-2y) = (2*8 + 2)/(8 - 2*2) = 18/4 = 9/2.
Since the result in the first case is 13/4 and the result in the second case is 9/2, INSUFFICIENT.
The correct answer is A.
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Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
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. Now I can understand my mistake.
