Is (r^2)x 0? (1) r^5 = 1 (2) x 0

Question

Is (r^2)x > 0?

(1) r^5 = 1
(2) x > 0

ChandlerBong · Answer

Asked:  ( r^2 )x > 0?

Basically, it asks whether x > 0.  r^2  will always be +ve]

Statement 1:   r^5  = 1.

No info on x and r can be 0 as well. Insufficient.

Statement 2:  x > 0.

Insufficient.

On combining: r = 1 and x > 0.

Answer: C.

cyrwr1 · Answer

R^2 always non-negative.

Stmt 1: r=1
Stmt 2: positive * non-negative = non-negative

Together: 1*positive = positive.

Posted from my mobile device

chetan2u · Answer

Statement II will not be sufficient when r=0. 
=> 0*x>0 or 0>0 ….. NO

chetan2u · Answer

Is (r^2)x > 0?

Conditions to be satisfied
 a)  r
eq 0 
b)  x>0

(1)  r^5 = 1  or r=1
Nothing about x
 
(2) x > 0
We don’t know whether r is 0.

Combined 
r=1 and x>0…..Answer is YES
Sufficient

JeffTargetTestPrep · Answer

We need to answer the question:

Is (r^2)x > 0 ?

Statement One Alone:

=> r^5 = 1

Since r^5 = 1, r is nonzero and r^2 is positive. We can rephrase the question by dividing both sides by r^2:

Is x > 0 ?

Clearly, we don’t have a definite answer to the rephrased question above.

Statement one is not sufficient. Eliminate answer choices A and D.

Statement Two Alone:

=> x > 0

If r ≠ 0, then (r^2)x = (positive)(positive) > 0, and the answer to the original question is Yes.

Whereas, if r = 0, then (r^2)x = (0)(positive) = 0, and the answer to the original question is No.

Statement two is not sufficient. Eliminate answer choice B.

Statements One and Two Together:

Since (r^2)x = (positive)(positive) > 0, the answer to the original question is a definite Yes.

The two statements together are sufficient.

Answer: C

Is (r^2)x > 0? (1) r^5 = 1 (2) x > 0