correct answer is (A).
B Since the question states that Rob is planning to bring his favorite guitar plus x additional
guitars, he will have a total of x + 1 guitars. The question states that the variable x
represents the number of additional guitars, so the number 1 must represent Rob’s favorite
guitar, which is (B).
D The best way to approach this question is through POE. According to the data in the table,
the ratio of those who enjoy biology to those who enjoy chemistry is 14 to 18, which can be
reduced to a ratio of 7 to 9; eliminate (A). The ratio of those who enjoy chemistry to those
who don’t enjoy chemistry is 18 to 6, which can be reduced to a ratio of 3 to 1; eliminate
(B). The ratio of those who enjoy biology to those who don’t enjoy chemistry is 14 to 6,
which can be reduced to a ratio of 7 to 3; eliminate (C). The ratio of those who don’t enjoy
biology to those who enjoy chemistry is 10 to 18, which can be reduced to a ratio of 5 to 9;
this matches (D).
C Dr. Goldberg takes 40% of substitute A, which consists of 60 grams. Mathematically, this
can be expressed as (60) or (0.4)(60) = 24 grams. She takes 70% of substitute B,which consists of 110 grams. Mathematically, this can be expressed as (110) or (0.7)(110) = 77 grams. Substitute C will therefore consist of 24 grams + 77 grams = 101 grams,
which is (C).
D To solve this question, simply factor out the largest value that fits within each of the terms
in the expression provided. In this case, x^4 , x^3 , and x^2 are all divisible by x^2 , so that is what
you will want to factor out. Doing so will leave you with x^2 (x^2 – x − 1), which is (D).
A Since Officer Blake drives 480 miles at a rate of 1 mile per minute, his total drive time was
480 minutes. The question asks for Officer Blake’s driving time in hours, so you need to
convert those minutes into hours. Since there are 60 minutes in 1 hour, you can divide 480
minutes by 60 to determine that Officer Blake drove for 8 hours, which is (A).
B The goal here is to isolate x. Since the right-hand side of the equation is –2x + 1, you will
want to subtract 1 from both sides, so eliminate (A) and (C). To get x by itself, you will
want to divide by –2, not 2, so eliminate (D) and choose (B). Remember that when you
multiply or divide across an inequality sign using a negative number, you need to flip the
inequality sign in the opposite direction, as reflected in (B).
C To solve this question, rearrange the expressions (2x^2 + 4x + 8) and (2x^2 – 4x + 7) in order
to place the similar terms next to each other. Doing so will give you 2x^2 – 2x^2 + 4x − (–4x)
- 8 – 7 (remember to distribute the negative sign for each of the terms in the second
expression). Simplifying this new expression will yield 0 + 8x + 1, or 8x + 1, (C). Another
way to approach this question would be to plug in a simple number for x, such as x = 2, and
match your target value with the values in the answer choices.