Correct Answer: A

Rationale: To solve for x, first, isolate x by moving the term involving x to one side of the equation. Begin by adding z to both sides of the equation to get (x/y) = rw + z. Then, multiply both sides by y to get x = y(rw + z), which simplifies to x = y(z + rw). Therefore, choice A is correct. Choices B, C, and D are incorrect because they do not correctly rearrange the terms in the equation to solve for x.

Correct Answer: C

Rationale: To find the force needed to stretch the coil 0.1 meters, we can set up a proportion based on the given information. The initial force and stretch are in direct proportion, so we can use this relationship to determine the unknown force. (132 N / 0.07 m) = X / 0.1 m. Cross-multiplying, we get 132 N * 0.1 m / 0.07 m = 188.57 N, which rounds to 188.6 N. Therefore, the correct answer is 188.6 Newtons. Choice A is incorrect as it does not match the calculated answer. Choice B is significantly higher and does not align with the proportional relationship. Choice D is close but does not account for the correct rounding as specified in the question.

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: D

Rationale: To convert yards to feet, you need to know that 1 yard is equal to 3 feet. Therefore, to find out how many feet are in 9 yards, you multiply 9 by 3, which equals 27 feet. Choice A (45 ft) is incorrect as it miscalculates by multiplying 9 by 5 instead of 3. Choice B (18 ft) incorrectly multiplies 9 by 2. Choice C (36 ft) is incorrect as it doubles the answer of 18 feet, which is also an incorrect calculation.

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.