If x and y are integers and x > 0, is y > 0?
(1) 7x - 2y > 0
(2) -y < x
A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is
sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
inequality
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(1) 7x - 2y > 0
==>
x > 2/7*y (*)
these values satisfy (*):
x = 1, y = 7 ==> y > 0
x = 1, y = -1/2 ==> y < 0
INSUFF
(2) -y < x
==>
x > -y (**)
these values satisfy (**) :
x = 1, y = 7 ==> y > 0
x = 1, y = -1/2 ==> y < 0
INSUFF
Note that these values satisfy both (*) and (**), but does not tell us distinctly if y < 0.
Ans: E
==>
x > 2/7*y (*)
these values satisfy (*):
x = 1, y = 7 ==> y > 0
x = 1, y = -1/2 ==> y < 0
INSUFF
(2) -y < x
==>
x > -y (**)
these values satisfy (**) :
x = 1, y = 7 ==> y > 0
x = 1, y = -1/2 ==> y < 0
INSUFF
Note that these values satisfy both (*) and (**), but does not tell us distinctly if y < 0.
Ans: E
- eaakbari
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(1)
y can be <0 or >0.
(2)
same case as (1). Try plugging positive and negative numbers
combined
tells us
8x>y
Insuff
Answer E
y can be <0 or >0.
(2)
same case as (1). Try plugging positive and negative numbers
combined
tells us
8x>y
Insuff
Answer E
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- Henry Ford
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If x and y are integers and x > 0, is y > 0?
(1) 7x - 2y > 0
(2) -y < x
x>0, x & y intergers
possible values: x : + only; y: +, -, 0
1) x> 2/7 y => y has to be a multiple of 7 for x to be an int => y: 7, -7, 0; x: +
x y x>0 7x-2y>0 y>0
3 7 y y y
3 -7 y y n
1 0 y y n
Insufficient
2) x: +, y: +, -, 0 => to be scenario values same in (1) & (2), take y: 7, -7,0
x y x>0 x+y>0 y>0
1 7 y y y
8 -7 y y n
2 0 y y n
Insufficient
1& 2) x: +, y: 7, -7, 0
x y x>0 7x-2y>0 x+y>0 y>0
3 7 y y y
3 -7 y n n
1 0 y y y
Insufficient (answer E)
Hope it helps. Need one clarification: 7x-2y>0 & x+y>0 => 8x>y (is it correct???)
(1) 7x - 2y > 0
(2) -y < x
x>0, x & y intergers
possible values: x : + only; y: +, -, 0
1) x> 2/7 y => y has to be a multiple of 7 for x to be an int => y: 7, -7, 0; x: +
x y x>0 7x-2y>0 y>0
3 7 y y y
3 -7 y y n
1 0 y y n
Insufficient
2) x: +, y: +, -, 0 => to be scenario values same in (1) & (2), take y: 7, -7,0
x y x>0 x+y>0 y>0
1 7 y y y
8 -7 y y n
2 0 y y n
Insufficient
1& 2) x: +, y: 7, -7, 0
x y x>0 7x-2y>0 x+y>0 y>0
3 7 y y y
3 -7 y n n
1 0 y y y
Insufficient (answer E)
Hope it helps. Need one clarification: 7x-2y>0 & x+y>0 => 8x>y (is it correct???)