could put up can be calculated as . Because this is the maximum number of unitsSai could put up, r has to be less than or equal to this number. Therefore, the correct answer
is (A).
C Weight is shown on the vertical axis of the graph, given in ounces. Make your own mark
indicating 5.75 on this axis; then draw a horizontal line from that mark to the line of best fit.
Once you hit it, draw a vertical line straight down to the horizontal axis. It should hit
between 75 and 80 days, slightly closer to the mark for 75. This makes (C) the correct
answer. Draw your lines carefully, using your answer sheet as a straightedge if necessary.
C Whenever the question includes variables, plug in. If s = 2, the shirts cost 2($24.50) = $49.
The tax on the shirts is 0.07($49) = $3.43. So, the shirts with tax and the $6 shipping fee
cost $49 + $3.43 + $6 = $58.43. Plug in 2 for s in the answers to see which answer equals
the target number of $58.43. In (A), 0.07[24.50(2) + 6] = 3.85. This is not the target
number, so eliminate (A). In (B), 1.07(24.50 + 6)(2) = 65.25. Again, this is not the target
number, so eliminate (B). In (C), 1.07[24.50(2)] + 6 = 58.43. This is the target number, so
keep it, but be sure to check the remaining answer choice. In (D), 1.07(24.50 + 2) + 6 =
34.355, which is not the target number. Therefore, the correct answer is (C).
B The question states that after 6 weeks the plant is 54 centimeters tall. Therefore, when w =
6, h(w) = 54. Plug in 6 for w in the answer choices to see in which one equals the target
number of 54. In (A), h(w) = 6(6) = 36. Eliminate (A). In (B), h(w) = 9(6) = 54. The
correct answer is (B).
D Because the operation between the parentheses is addition, the parentheses can be removed,
and the resulting expression becomes 12x^2 + 4x + 5y + 3x^2 – 2x + 3y. Reorder the terms so
that like terms are next to each other: 12x^2 + 3x^2 + 4x − 2x + 5y + 3y. Combine like terms to
get 15x^2 + 2x + 8y. The correct answer is (D).
D You do not know how the survey is conducted, nor do you know how many veterinarians
were surveyed (it may be the case that only 8 were surveyed). Therefore, you cannot infer
that the survey accurately measures all veterinarians’ beliefs about Royal Rat Rations.
Choice (A) is not supported. First, you do not know what veterinarians believe in general,
and second, veterinarians may be recommending Royal Rat Rations for a reason other than
its nutrition. Choice (B) is similarly not supported: Besides not knowing veterinarians’
beliefs, this choice assumes that no other rat food is acceptable. Choice (C) is not
supported because you do not know the sample size of the survey, nor is there any
indication that there is only one veterinarian who does not recommend Royal Rat Rations.
Choice (D) is the correct answer: You know the opinions only of the veterinarians surveyed
by Royal Rat Rations.
D Use a calculator to translate the fractions into decimals. t + 4 = t – 5 becomes 0.5t + 4 =
0.75t – 5. Subtract 0.5t from both sides to get 4 = 0.25t – 5, and then add 5 to both sides.