Data Sufficiency

If x is positive, is x>3?
a) (x-1)^2 > 4
b) (x-2)^2 > 9

If x is positive, is x>3?

a) (x-1)^2 > 4

Implies (x-1)>2 or (x-1)<-2
x>3 or x<-1. But we already know that x>0. So, x is definitely greater than 3. Statement 1 is sufficient to answer the question.

b) (x-2)^2 > 9

Implies (x-2)>3 or (x-2)<-3
x>5 or x<-1. But we already know that x>0. So, x is definitely greater than 3(greater than 5 to be precise). Statement 2 is sufficient to answer the question.

IMO D

If x is positive, is x>3?
a) (x-1)^2 > 4
b) (x-2)^2 > 9


Statement 1: (x-1) > 4 then (x-1) > 2 OR (x-1) < -2

Therefore, x > 3 OR x < -1

But we are given the condition that if x is positive,

then x has to be greater than 3.

Hence sufficient...


Statement 2: (x-2)^2 > 9 then (x-2) > 3 OR (x-2) < -3

Therefore, x > 5 OR x < -1

Because we are given the condition that if x is positive,

then x cannot be less than -1,

Hence x > 5 and hence greater than 3.

Sufficient...


Certainly the answer turns out to be D.

Hope this post actually helps you...