gmat prep DS question

[career.sumit]

if -2x > 3y, is x negative ?

(1) y>0
(2) 2x+5y-20 = 0

source gmatprep
I encountered this DS question on gmatprep software.
I got the answer as A, but the correct one is D.
Please explain how the second option is correct

the way i approached it -
st (1) y>0
since y is positive, hence 3y is positive and to satisfy the inequality, the RHS part should be positive(-2x should be positive), x should be negative.
hence st (1) sufficient

st (2) 2x + 5y - 20 = 0
here i tried plugging numbers.
for y=6 and x= -5, equation is satisfied
and
for y= 2 and x=5, equation is satisfied....
since x is both positive and negative, this statement is not sufficient.

Since OA is D , i am doing it wrong.
Instructors please correct me

[gupviv23]

Hi

st (1) y>0
since y is positive, hence 3y is positive and to satisfy the inequality, the RHS part should be positive(-2x should be positive), x should be negative.
hence st (1) sufficient

st(2)
2x+5y-20=0
2x=20-5y

Now, -2x>3y
2x<-3y
Plug value of 2x=20-5y here
20-5y<-3y
20<2y
y>10
which shows y is positive, so x has to be negative
hence st(2) is sufficient

So, both statements are sufficient and answer is (D)

[smohit04]

ditto..

@career.sumit - you only considered statement 2 to solve the equation but we should always consider the given condition AND the statement together to find the solution.

[career.sumit]

mohit... thanks for pointing out my mistake. I will take care not to repeat it in future.

[RonPurewal]

please search the forums, folks -- thanks

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