The following GMAT Problem Solving question tests your understanding of functions and how to manipulate algebraic expressions.

Question 28:

The function $f(x) = \dfrac{\left(x-\dfrac{1}{x}\right)}{\left(x+\dfrac{1}{x}\right)}$ is defined for all values of $x \neq 0$. Which of the following is equal to $f\left(-\dfrac{1}{x}\right)$?

1. $\quad -f(x)$
2. $\quad -f(-x)$
3. $\quad f(x)$
4. $\quad -f\left(\dfrac{1}{x}\right)$
5. $\quad f\left(\dfrac{1}{x}\right)$

 
The following GMAT data sufficiency question tests your understanding of dealing with remainder questions and their formulation in the context of data sufficiency.

Question 27:

Is the positive integer $n$ divisible by $15$ ?

1. (1) When $n$ is divided by $10$ the remainder is $5$.
2. (2) When $n$ is divided by $6$ the remainder is $3$.

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.

 
The following GMAT data sufficiency question tests your understanding of straight lines and intercepts in the $xy-$coordinate plane.

Question 26:

In the $xy$-plane, what is the slope of the line $y=mx+c$, where $mc \neq 0$ ?

1. (1) The $x$ and $y$-intercepts of the line are equal.
2. (2) The product of the $x$ and $y$-intercepts is equal to $1$.

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.

 
The following GMAT Problem Solving question tests your understanding of how to find the measure of an angle in a regular pentagon.

Question 25:

The figure below shows a regular pentagon. What is the measure of angle $ACE$ ?

1. $\quad 18$
2. $\quad 24$
3. $\quad 36$
4. $\quad 40$
5. $\quad 45$