What is the value of x^8

Question

What is the value of  x^8  ?

(1)  x^2=16 
(2)  x<0

chetan2u · Answer

ans A...
statement 1 gives the value as 16^4

GMATinsight · Answer

Statement 1: x^2 = 16 
i.e. x =  + 4

But for both x= + 4, x^8 will have same value therefore
SUFFICIENT

Statement 2: x<0 
for uncertain value of x, the value of x^8 will also be uncertain therefore
NOT SUFFICIENT

Answer: Option  A

Kinshook · Answer

S1: 
 x^2 = 16 
 => x^8 = (x^2)^4 = 16^4 
SUFFICIENT

S2:
x<0
 x^8  may take any value depending on |x|
INSUFFICIENT.

IMO A

Prep Toolkit