Correct Answer: A

Rationale: A histogram is the best way to display the frequency for each day of the week in this scenario. Histograms are ideal for showing the distribution of numerical data by dividing it into intervals and representing the frequency of each interval with bars. In this case, each day of the week can be represented as a category with the frequency of students getting up after 8 a.m. displayed on the vertical axis. Choice B, a pie chart, would not be suitable for this scenario as it is more appropriate for showing parts of a whole, not frequency distributions. Choice C, a bar graph, could potentially work but is more commonly used to compare different categories rather than displaying frequency distribution data. Choice D, a scatter plot, is used to show the relationship between two variables and is not the best choice for displaying frequency for each day of the week.

Correct Answer: B

Rationale: To solve the equation, distribute 3 to both terms inside the parentheses: 6x + 15 = 11x + 5. Then, move 11x to the left side by subtracting it from both sides: 6x - 11x = 5 - 15. Simplify to get -5x = -10. Divide by -5 to isolate x: x = 2. Therefore, the correct answer is x = 2. Choices A, C, and D are incorrect because they do not match the correct solution obtained by solving the equation step by step.

Correct Answer: D

Rationale: To find the cost of one syringe, divide the total cost by the number of syringes: $660.00 · 55 = $12. Therefore, the cost of four syringes is 4 x $12 = $48. Choices A, B, and C are incorrect because they do not correctly calculate the cost per syringe or the total cost of four syringes.

Correct Answer: B

Rationale: The correct answer is B: 1. The average width of a doorway typically ranges from 0.8 to 1.2 meters, making 1 meter a reasonable estimate. Choice A (0.5) is too narrow for a standard doorway. Choice C (10) is too wide for a typical doorway. Choice D (3) is also wider than the standard width of a doorway.

Correct Answer: A

Rationale: The correct answer is A: 'A number divisible by only 1 and itself.' A prime number is a natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers. This definition aligns with choice A. Choice B is incorrect because not all prime numbers are divisible by 2 and 3. Choice C is incorrect as prime numbers are not divisible by any number other than 1 and themselves. Choice D is incorrect because a prime number has exactly two factors, 1 and itself, not three factors.