# Errata

This page contains a list of typos or errors from my books. If you think you've found an error, please let me know through the contact page. The edits will be incorporated in future editions.

#### SAT Math: The Advanced Guide and Workbook

Chapter 3 Exponential vs. Linear Growth, #3 (pg. 26): The answer explanation on page 260 has a typo. The rate should be $$1 - 0.06 = 0.94$$.

Chapter 7 Constructing Models, #1 (pg. 47): The question should read "... and then lays $$\dfrac{x}{2}$$ bricks per hour for $$2y$$ more hours."

Chapter 21 Triangles, #14 (pg. 184):The diagram is drawn incorrectly, though it's hard to tell. The diagram should be drawn so that triangle $$ABC$$ is similar to triangle $$DEF$$ (and the sides should correspond).

Chapter 23 Trigonometry, #12 (pg. 207): The answer explanation on page 310 has a typo. In quadrant III, sine and cosine are both negative (not positive).

Chapter 25 Probability, #10 (pg. 223): The first sentence of the question should read "A manufacturer uses two assembly lines to produce refrigerators."

#### SAT Writing: Advanced Guide and Workbook

Chapter 6 Subject Verb Agreement, Exercise 3, #3 (pg. 26): This question needs to be revised as the answer is unclear. "A variety" can take a singular or plural verb depending on the context and the emphasis. For this question, the answer could be either singular or plural. The good news is that the SAT won't test you on this distinction.

Chapter 18 Word Choice, Example 6 (pg. 108): The "to" in the question sentence should not be underlined.

#### SAT Math: 10 Practice Tests

Practice Test 1, Section 3, #2: The answer is correct but here's the correct explanation: $$\dfrac{\dfrac{1}{x}}{x + 3} = \dfrac{1}{x}\div (x + 3) = \dfrac{1}{x}\times\dfrac{1}{x + 3} = \dfrac{1}{x(x + 3)}$$

Practice Test 1, Section 3, #3: The answer is correct but here's the correct explanation: The equation is satisfied only when $$x = 2, y = 3$$, and $$z = -4$$. So, $$x + y + z = 2 + 3 + (-4) = \boxed{1}$$.

Practice Test 2, Section 3, #19: The question should read the expression above is equivalent to $$\dfrac{k}{x(x - 3)^2}$$ (NOT $$\dfrac{k}{(x - 3)^2}$$)

#### ACT Math: Advanced Guide and Workbook

Chapter 1 Absolute Value, #7 (pg. 8): The correct answer is C, not E.

Chapter 6 Properties of Numbers, Example 6 (pg. 35): The correct answer should be $$\dfrac{3}{25} = 12\%$$, since only 3 numbers (10, 32, and 54) are even.