153 - 159 Arithmetic Properties and Inequalities

[phoenix9801]

152- If x is an integer is x IxI < 2^x

(1) x < 0

(2) x = -10



note: the answer is D. , but I am having trouble to understand what is the question is asking? Can someone please explain in the simplest way and in depth please and how you would solve both statements.




159 - x < 0, is Y > 0 ?

(1) x/y < 0

(2) y-x > 0


Note : Is there any way you can solve this by using picking numbers or any other that is very simple please???

[selango]

159 - x < 0, is Y > 0 ?

(1) x/y < 0

(2) y-x > 0

x<0

y>0?

From stmt1,

x/y<0

Since x<0,y must be greater than 0 to satisfy the inequality.

Sufficient.

From stmt2,

y-x>0

y>x

x=-2,y=1,y>0

x=-2,y=-1,y<0

Insuffcient.

Hence A

[selango]

152- If x is an integer is x IxI < 2^x

(1) x < 0

(2) x = -10


x*|x|<2^x

If x<0,x*(-x)<2^x=x^2>-2^x

If x>0,x^2<2^x

From stmt1,

x<0

So x^2>-2^x

Sufficient.

From stmt2,

x=-10

-10*10<2^10

100>1/2^10

Sufficient.

Hence D

[aloneontheedge]

159 - x < 0, is Y > 0 ?

(1) x/y < 0

(2) y-x > 0

x<0

y>0?

From stmt1,

x/y<0

Since x<0,y must be greater than 0 to satisfy the inequality.

Sufficient.

From stmt2,

y-x>0

y>x

x=-2,y=1,y>0

x=-2,y=-1,y<0

Insuffcient.

Hence A

Selango,
Am i reading the question wrong?
it says -x < 0 which means x is positive
stmnt 1 : x/y < 0
since x is positive, y must be negative -->Suff
stmnt 2: y-x > 0 y>x
since x is positive y has to be positive --> Suff
Hence D

[aleph777]

Selango,

I misread that ' - ' as a negative sign at first, too. It's just how phoenix separated the question from the problem, though. You'll notice the same marking for the first question listed.

So the question simply reads:

x < 0, is y > 0?

and in that case, statement 1 is suf and 2 is insuf.

[/quote]

[aloneontheedge]

Selango,

I misread that ' - ' as a negative sign at first, too. It's just how phoenix separated the question from the problem, though. You'll notice the same marking for the first question listed.

So the question simply reads:

x < 0, is y > 0?

and in that case, statement 1 is suf and 2 is insuf.

[/quote]
I agree.
A is the answer.
what a misinterpretation!!!!