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

by **Guest** Sat Sep 06, 2008 5:43 pm

DS: if -2x > 3y, is x negative?
1) y>0
2) 2x+5y-20=0

D is the correct answer.

by **divya** Sat Sep 06, 2008 10:55 pm

DS: if -2x > 3y, is x negative?
1) y>0
2) 2x+5y-20=0

if -2x > 3y --- EQ 1 ---- > is x < 0

1. y > 0 , then 3y > 0 , so if -2x > 0 , x has to be -ve ( -ve * -ve = +ve ) Thus A. is sufficient
2. 2x + 5y - 20 = 0
2x = -5y + 20
x = (-5y + 20 ) / 2
Substituting that in eq 1
-2 * (-5y + 20 ) / 2 = 5y -20 > 3y
2y > 20
y > 10
if y is > 10, then looking at eq 1 again , x have to be < 0 for it to be greater than 3y ( +ve number). Thus B. is sufficient

Therefore answer: D

by **Guest** Fri Sep 12, 2008 12:33 pm

Thank you so much! i totally get it now. Divya, you rock! thanks,

by **RonPurewal** Tue Sep 30, 2008 5:37 am

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