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

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

**Video Explanation**