## 1.

The Correct Answer is (D) — You can pick any two points on the graph and divide the rise (change in y-values) by the run (change in x-values) to find the slope. For example, you can see that at 4 days the sprout’s height is 6 cm, giving you the point (4,6). At 8 days the sprout’s height is 7 cm, giving you the point (8,7). You can find that the slope is $\frac{7-6}{8-4}&space;=&space;\frac{1}{4}$, meaning that 1cm of growth happens every 4 days.

## 2.

The Correct Answer is (D) — The line y = 2x – 7 has a slope of 2, so you need to decide which of the answer choices also has a slope of 2. By rearranging the answer options into the form y = mx + b, where m is the slope, you can see that (A) has a slope of 1, (B) has a slope of -2, (C) has a slope of ½, and (D) has a slope of 2. Therefore, (D) is correct.

## 3.

The Correct Answer is (C) — To find the y-intercept, simply set x = 0 and solve for y. This gives you 3y + 5(0) - 3 = 0, so y = 1.

## 4.

The Correct Answer is (C) — Since half of the 4,600 languages have writing systems, there are 2,300 languages with writing systems. Of these, 23 use Arabic script. As a percentage, this is 23/2,300 = 0.01 = 1%.

## 32.

The Correct Answer is (4) — If |x| = x + 8, either x = x + 8 or -x = x + 8. The first case reduces to 8 = 0, so it is impossible. The second case reduces to x = -4, so -x = 4.

## 33.

The Correct Answer is (140) — Since a and c are opposite angles, they are equal. Since their sum is 80 degrees, they must each be 40 degrees. Finally, since L and S are parallel, you know that b and a are supplementary angles, meaning they add to 180°. This means that b = 180° - 40° = 140°.

## 34.

The Correct Answer is (66) — You can model the number of bees that survive the winter with the expression 30,000 + 500h, where h is the number of ounces of honey the beekeeper adds to the hive. Setting 30,000 + 500h = 63,250, you can solve for h = 66.5. Since the question is asking for the maximum whole number of ounces that can be added, the answer is 66.

## 35.

The Correct Answer is (5) — Since the proposed road would be 4 kilometers long and would reduce the total travel time between Elon and McCormack by half, you know that the distance along the current roads from Elon to McCormack is 8. You can notice that the roads form a 3-4-5 special triangle (since 3 + 5 = 8), so the distance from Springton to McCormack is 5.
If you don’t notice this, you can let x be the distance from Springton to McCormack and use the Pythagorean Theorem to find that (8 - x)2 + 42 = x2, which you can solve to get x = 5.

## 36.

The Correct Answer is (2) — Since Lauren can fit 2 books in a box with volume x3 and 16 books in a box with volume (kx)3 = k3x3, you know that the larger box is 8 times as big as the smaller box, so k3 = 8, meaning that k = 2.

## 37.

The Correct Answer is (9/2 or 4.5) — You can see on the dot plot that the fastest robot cleaned 100% of the floor in 30 minutes, while the slowest robot only cleaned 30% of the floor. The robots’ speed is proportional to the percentage of the floor they cleaned, so 100/30 = 15/x, where x is the speed, in square feet per minute, of the slowest robot. You can cross-multiply and solve this equation to get x = 4.5.

## 38.

The Correct Answer is (75) — The first step is to find the median efficiency, which you can do by examining the dot plot and repeatedly crossing off the highest and lowest dots. After you have crossed 11 dots on each side, there will be one dot remaining, in the “70” column. This means that a robot with the median efficiency cleans 70% of the room in 30 minutes. To find out how much is cleaned in 75 minutes, simply multiply 70% of the room × (75 mins)/(30 mins) = 175% of the room. The question is asking for the percentage of the room that gets cleaned twice, so this is 175% - 100% = 75%.