Data Sufficiency

Is P a negative number?
1. p3(1-p2) < 0
2. p2-1 <0

p3 -> cube of p
p2 -> square of p

Hi!

IMO C

(1) p^3(1 - p^2) < 0
p^3(1 - p)(1 + p) < 0 /p^2
We can divide both sides by p^2 because p is not equal to 0
p(1 - p)(1 + p) < 0
-1 < p < 0 or p > 1
Statement (1) ALONE is NOT SUFFICIENT

(2) p^2 - 1 < 0
(p - 1)(p + 1) < 0
-1 < p < 1
Statement (2) ALONE is NOT SUFFICIENT

(1) & (2)
(-1 < p < 0 or p > 1) & (-1 < p < 1)
Therefore, -1 < p < 0
BOTH statements TOGETHER are sufficient

Hope it helps!
Best,
Maciek

Another approach.

Combining 1 and 2,

p^2-1<0 or 1-p^2>0

p^3(1 - p^2) < 0

Since 1-p^2>0,p^3 must be -ve in order for the above equation to be negative.

p^3<0-->p<0 [odd power raised to negative number results in negative.]

Pick C

yesterday I was seeing this one in Grockit...

Good approach Anand~