Is x0? 1) x^2+x-20 2) x^3

Question

Is x>0?
1) x^2+x-2>0
2) x^3<x^2
(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) Statement 1 and statement 2 together are not sufficient

Ravshonbek · Answer

Is x>0? 1) x^2+x-2>0 2) x^3

pmenon · Answer

C

Stat 1 says x=-2 or x=1. insuff

stat 2 says that x<1 or x<0

together, only x=-2 satisfies, so x<0

neelesh · Answer

I think the answer is B,

From 1)  x \in (-\infty, -2) U (1,\infty) . Hence it cannot be established if x > 0

From 2)  x \in (0, 1) . Sufficient.

Ans. B

pmenon · Answer

Well, for stat 2, x could either be a positive element that is between 0 and 1, or, it could just be less than 1.

Unless I'm missing something, I don't think stat 2 by itself is enough.

What do you guys think ?

neelesh · Answer

Between 0 and 1 and less than 1 means x>0.

GMATBLACKBELT · Answer

Ans can't be B.

x can be 1/2 or -5. Thus x>0? Yes and No.

I vote for C as well.

neelesh · Answer

You are right guys...

My domain for statement 2 is incorrect.....
It should be

x \in (-\infty, 1) .

Answer should be C.

I think I should go to sleep now...Too many mistakes for the day.

Is x>0? 1) x^2+x-2>0 2) x^3<x^2 (A) Statement 1

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