, which is (B).
D If two patients are added to the trial, there will be 12 total patients. If the mean height of 12
patients is 169 cm, then the 12 patients have a total height of 12 × 169 = 2,028 cm. The total
height of the first 10 patients is 184 + 176 + 181 + 157 + 168 + 154 + 148 + 165 + 190 +
162 = 1,685 cm, so the two new patients must have a total height of 2,028 – 1,685 = 343
cm. Add up the heights and eliminate any choice that does not equal 343. Only (D) works.
D Plugging in the given point to see which equation is true is not easy on this one, since both
values have weird decimals. The answer choices are also likely written so that more than
one that point, so try to find another point on the line. The x-intercept of a line is where the
line crosses the x-axis. At that point, the value of y is 0. Therefore, (2, 0) is also a point on
the line. Plug this point into the answers, since it is easier to calculate. If it works in more
than one equation, plugging in the ugly point will determine the correct answer, which must
work for both points work. Plug point (2, 0) into (A) to get 0 + 5.9 = 2.5(2). Solve both
sides of the equation to get 5.9 = 5. Eliminate (A). Plug (2, 0) into (B) to get 4(0) + 12(2) =
29.1. Solve both sides of the equation to get 4 + 24 = 29.1, or 28 = 29.1. Eliminate (B).
Plug (2, 0) into (C) to get 6(0) + 27.15 = 12(2). Solve both sides of the equation to get 0 +
27.15 = 24. Since this is clearly not a true statement, eliminate (C). Plug (2, 0) into (D) to
get 10(0) – 13(2) = –26. Solve both sides of the equation to get –26 = –26. Since (D) is the
only answer for which the point (2, 0) works, the correct answer is (D).
B Whenever there are variables in the question and in the answers, think Plugging In. If P 0 =
4, k = 2, and t = 3, then P = (4)(10)^6 = 4,000,000. Plug these values into the answer choicesto see which answer works. Choice (A) becomes 3 = . Simplify the rightside of the equation to get 3 = , then 3 = , and finally 3 = –3. This isn’ttrue, so eliminate (A). Choice (B) becomes 3 = . Simplify the right sideof the equation to get 3 = , then 3 = , and finally 3 = 3. Keep (B), butcheck the remaining answer choices just in case. Choice (C) becomes 3 = . Simplify the right side of the equation to get 3 = ,
or 3 ≈ 3.6. Eliminate (C). Choice (D) becomes 3 = 2 log . Simplify the right