Nursing Elites

1. Simplify (x^2 - y^2) / (x - y)

• A. x + y
• B. x - y
• C. 1
• D. (x + y)/(x - y)

Correct answer: A

Rationale: The expression 𝑥^2 - 𝑦^2 is a difference of squares, which follows the identity: 𝑥^2 - 𝑦^2 = (𝑥 + 𝑦)(𝑥 - 𝑦). Therefore, the given expression becomes: (𝑥^2 - 𝑦^2) / (𝑥 - 𝑦) = (𝑥 + 𝑦)(𝑥 - 𝑦) / (𝑥 - 𝑦). Since (𝑥 - 𝑦) appears in both the numerator and the denominator, they cancel each other out, leaving 𝑥 + 𝑦. Thus, the simplified form of (𝑥^2 - 𝑦^2) / (𝑥 - 𝑦) is 𝑥 + 𝑦. Therefore, the correct answer is A (x + y). Option B (x - y) is incorrect as it does not result from simplifying the given expression. Option C (1) is incorrect as it does not account for the variables x and y present in the expression. Option D ((x + y)/(x - y)) is incorrect as it presents the simplified form in a different format than the correct answer.

2. A farmer had about 150 bags of potatoes on his trailer. Each bag contained from 23 to 27 pounds of potatoes. What is the best estimate of the total number of pounds of potatoes on the farmer’s trailer?

• A. 3,000 pounds
• B. 3,700 pounds
• C. 4,100 pounds
• D. 5,000 pounds

Correct answer: B

Rationale: To estimate the total number of pounds of potatoes on the farmer's trailer, we can use the average weight of a bag of potatoes. The average weight is calculated by adding the minimum and maximum weights of the bags and dividing by 2: (23 + 27) / 2 = 25 pounds. Next, multiply the average weight by the total number of bags: 25 pounds/bag * 150 bags = 3,750 pounds. Therefore, the best estimate of the total number of pounds of potatoes on the farmer's trailer is 3,750 pounds. Choice A (3,000 pounds) is too low as it underestimates the total weight. Choice C (4,100 pounds) and Choice D (5,000 pounds) are too high as they overestimate the total weight.

3. This chart indicates the number of sales of CDs, vinyl records, and MP3 downloads that occurred over the last year. Approximately what percentage of the total sales was from CDs?

• A. 55%
• B. 25%
• C. 40%
• D. 5%

Correct answer: C

Rationale: To determine the percentage of CD sales out of the total sales, we need to consider the total sales of CDs, vinyl records, and MP3 downloads. To find the percentage of CD sales, we divide the total sales of CDs by the sum of total sales of CDs, vinyl records, and MP3 downloads, and then multiply by 100. In this case, the correct calculation shows that CDs accounted for 40% of the total sales. Choice A (55%) is incorrect as it overestimates the contribution of CDs. Choice B (25%) is incorrect as it underestimates the percentage of CD sales. Choice D (5%) is also incorrect as it severely underestimates the share of CD sales in the total sales.

4. Which of the following equations does not represent a function?

• A. y = x^2
• B. y = sqrt(x)
• C. x = y^2
• D. y = 2x + 1

Correct answer: C

Rationale: An equation represents a function if each input (x-value) corresponds to exactly one output (y-value). In the equation x = y^2, for a single x-value, there are two possible y-values (positive and negative square root), violating the definition of a function. This violates the vertical line test, where a vertical line intersects the graph in more than one point for non-functions. Choices A, B, and D all pass the vertical line test and represent functions, making them incorrect answers.

5. What is a direct proportion? What is an inverse proportion?

• A. Direct: Both quantities increase or decrease together; Inverse: When one quantity increases, the other decreases by the same factor
• B. Direct: Both quantities decrease together; Inverse: When one quantity increases, the other increases
• C. Direct: One quantity stays the same while the other increases; Inverse: Both quantities increase together
• D. Direct: One quantity increases while the other decreases; Inverse: Both quantities decrease together

Correct answer: A

Rationale: In a direct proportion, both quantities increase or decrease together. This means that as one quantity goes up, the other also goes up, and vice versa. On the other hand, in an inverse proportion, when one quantity increases, the other decreases by the same factor. Therefore, choice A is correct as it accurately defines direct and inverse proportions. Choices B, C, and D are incorrect because they do not accurately describe the relationship between quantities in direct and inverse proportions.

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