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Bunuel, If I put 2 in Stmt 1 then it comes true. So stmt 1 also shows p>1.

Where am I wrong?
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The fastest way to solve this problem is to plot a graph. I would love to help but I lack right now the resources to post a picture. :oops: I believe that Bunuel will soon show up and help us.

I will try to explain anyway:

(1) Consider three parallel number lines (p) , one for \(p^3\), one for \(1-p^2\) and a third one to represent the product of the these two functions. The "+" and "-" represents the sign (Y) of the functions.

A: \(p^3\):-------(-1)---0+++(+1)++++
B: \(1-p^2\):----(-1)+++0+++(+1)-----
A*B:++++++++(-1)---0+++(+1)----- --> So p can be either positive or negative = Insuff.

(2) \(p^2 - 1\) ++++(-1)---(0)---(+1)++++++ Same as in (1), p can be either positive or negative = Insuff.

(1) and (2) together shows a clear intersection when p < 0, so Suff.
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Wow, I was writting my reply and in the mean time you guys had already posted ! :o
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Hussain15
Bunuel, If I put 2 in Stmt 1 then it comes true. So stmt 1 also shows p>1.

Where am I wrong?

Statement (1) is true for: \(p>1\) (1.5, 2, 7, 12.5, ...) AND \(-1<p<0\) (-1/2, -3/4, ...).
Statement (2) is true for: \(-1<p<1\) (-5/6, -2/9, 0, 1/2, 3/4, 7/8, ...).

----(-1)----(0)----(1)----
----(-1)----(0)----(1)----


Combined:

----(-1)----(0)----(1)----
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shouldn't the question be

is p negative??

in the above solution we considered "p" in the range -1<p<0
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FedX
shouldn't the question be

is p negative??

in the above solution we considered "p" in the range -1<p<0

Question: is \(p\) negative? Is \(p<0\)?

When we considered statements together we've got that \(-1<p<0\): every \(p\) from this range is negative (every \(p\) from this range is \(<0\)). Hence taken together statements are sufficient.

Answer: C.

Hope it's clear.
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Bunuel
FedX
shouldn't the question be

is p negative??

in the above solution we considered "p" in the range -1<p<0

Question: is \(p\) negative? Is \(p<0\)?

When we considered statements together we've got that \(-1<p<0\): every \(p\) from this range is negative (every \(p\) from this range is \(<0\)). Hence taken together statements are sufficient.

Answer: C.

Hope it's clear.

This is fine..but the original poster has put it as "Is p a negative number"?
Do they both mean the same??
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FedX
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FedX
shouldn't the question be

is p negative??

in the above solution we considered "p" in the range -1<p<0

Question: is \(p\) negative? Is \(p<0\)?

When we considered statements together we've got that \(-1<p<0\): every \(p\) from this range is negative (every \(p\) from this range is \(<0\)). Hence taken together statements are sufficient.

Answer: C.

Hope it's clear.

This is fine..but the original poster has put it as "Is p a negative number"?
Do they both mean the same??

The questions "is \(p\) negative" and "is \(p\) a negative number" are the same. Maybe you confused "number" with "integer"?
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Thanks for the clarification Bunuel !!.
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C should be the correct answer, just see the following counterexamples:
statement 1: p=2
statement 2: p=-0.1

Considering both statements, p3 must be negative then p negative
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zest4mba
Is p a negative number?

(1) p^3(1 – p^2) < 0
(2) p^2 – 1 < 0

1) the inequality holds true for +ve numbers as well as -1<p<0
so insufficient.

2) the inequality holds true for 0<p<1 & -1<p<0 or -1<p<1
so insufficient.

(1)+(2)
(2) says p^2 - 1 < 0
or (1-p^2) > 0
plugging that in 1, we get p^3(positive quantity) < 0
or p^3 < 0
which means p < 0
hence sufficient.
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