Gmat Prep test problem

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Source: — Data Sufficiency |

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by kmittal82 » Mon Sep 27, 2010 6:07 am
Stm1)

n > -1

This does not give any information about p, so not sufficient

Stmt 2)

np > 0

This means either both n and p are positive, or n and p are negative. Again, using just this information, p could be +ve or -ve, so not sufficient

combining 1 + 2, we know that n > -1 i.e. n could be negative or positive, and stmt 2 tells u p is np is positive, which means p could be either negative or positive. this is unsufficient to answer the question.

Hence (E)

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by tlt2372 » Mon Sep 27, 2010 8:17 am
sdotcruz wrote:If n and p are integers, is p>0?

(1) n+1 > 0

(2) np > 0

can someone break it down for me?
IMO C

Statement 1 tells us that n is positive. But tells us nothing about p.

Statement 2 tells us that either n and p are both positive or both negative.

Taken together, from Statement 1, n is positive, from statement 2, when n is positive, p is positive. P>0
Therefore the answer is C.

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by kmittal82 » Mon Sep 27, 2010 9:17 am
tlt2372 wrote:
sdotcruz wrote:If n and p are integers, is p>0?

(1) n+1 > 0

(2) np > 0

can someone break it down for me?
IMO C

Statement 1 tells us that n is positive. But tells us nothing about p.

Statement 2 tells us that either n and p are both positive or both negative.

Taken together, from Statement 1, n is positive, from statement 2, when n is positive, p is positive. P>0
Therefore the answer is C.
ah you're right, I missed the part which says they are "integers" :(.. I was also considering -0.5 and so on... should be (C)