Nursing Elites

1. 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.

2. The cost, in dollars, of shipping x computers to California for sale is 3000 + 100x. The amount received when selling these computers is 400x dollars. What is the least number of computers that must be shipped and sold so that the amount received is at least equal to the shipping cost?

• A. 10
• B. 15
• C. 20
• D. 25

Correct answer: B

Rationale: To find the least number of computers that must be shipped and sold so that the amount received is at least equal to the shipping cost, we set up the inequality 400x >= 3000 + 100x. Simplifying this inequality gives 300x >= 3000, and dividing by 300 results in x >= 10. Therefore, at least 15 computers must be shipped and sold to cover the shipping cost, making choice B the correct answer. Choices A, C, and D are incorrect as they represent numbers less than 15, which would not cover the shipping cost.

3. How many gallons are in 1,000 fluid ounces?

• A. 7.8125 gallons
• B. 15.625 gallons
• C. 31.25 gallons
• D. 62.5 gallons

Correct answer: A

Rationale: To convert fluid ounces to gallons, you need to divide the number of fluid ounces by the number of fluid ounces in a gallon. Since there are 128 fluid ounces in a gallon, to find out how many gallons are in 1,000 fluid ounces, you divide 1,000 by 128. The correct calculation is 1,000 / 128 = 7.8125 gallons. Therefore, the correct answer is A. Choices B, C, and D are incorrect as they do not accurately represent the conversion from fluid ounces to gallons.

4. 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.

5. What defines a proper fraction versus an improper fraction?

• A. Proper: numerator < denominator; Improper: numerator > denominator
• B. Proper: numerator > denominator; Improper: numerator < denominator
• C. Proper: numerator = denominator; Improper: numerator < denominator
• D. Proper: numerator < denominator; Improper: numerator = denominator

Correct answer: A

Rationale: A proper fraction is characterized by having a numerator smaller than the denominator, while an improper fraction has a numerator larger than the denominator. Therefore, choice A is correct. Choice B is incorrect because it states the opposite relationship between the numerator and denominator for proper and improper fractions. Choice C is incorrect as it describes a fraction where the numerator is equal to the denominator, which is a different concept. Choice D is incorrect as it associates a numerator being smaller than the denominator with an improper fraction, which is inaccurate.

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