Subscribe To This Site
Data-Sufficiency
Does y = 3?
(1) The average (arithmetic mean) of x, y and z is 0.
(2) X + -y.
From, Statement (1) alone, we get x + y + z = 0.
We can not say from this equation whether y = 3 or not.
So, Statement (1) alone does not help us to answer the question as YES or NO uniquely.
So, (A) is not the answer.
From Statement (2), we get that x + y =0.
This by itself can help us to answer the question whether y = 3 or not.
So, Statement (2) alone does not help us to answer the question as YES or NO uniquely.
So, (B) is not the answer.
But, if both the Statements (1) and (2) are taken together, we can not uniquely conclude that z = 0. Here we can not say anything about y.
So, both the statement together will not help us to answer the question as YES or No uniquely.
So, as per the instructions, (E) is the answer.
