GMAT Data Sufficiency Question 05: Arithmetic mean

 
The following GMAT data sufficiency question tests your understanding of average (arithmetic mean) in the context of being able to manipulate algebraic expressions and observe patterns.

Question 5:

What is the average (arithmetic mean) of $x$, $y$, and $z$ ?

1. (1) The average of $2x-5$, $2y-5$, $2z-5$ is $25$.
2. (2) The average of $2x-y$, $4y+3z$, and $x+9$ is $48$.

1. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
2. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
3. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
4. EACH statement ALONE is sufficient.
5. Statements (1) and (2) TOGETHER are NOT sufficient.