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. Solve for x: 2x + 6 = 14

• A. x = 4
• B. x = 8
• C. x = 10
• D. x = 13

Correct answer: A

Rationale: To solve the equation 2x + 6 = 14, you first subtract 6 from both sides to isolate 2x. This gives 2x = 8. Then, divide by 2 on both sides to find x. Therefore, x = 4. Choices B, C, and D are incorrect as they do not correctly follow the steps of solving the equation.

3. Simplify the following expression: (1/4) × (3/5) ÷ 1 (1/8)

• A. 8/15
• B. 27/160
• C. 2/15
• D. 27/40

Correct answer: C

Rationale: First, convert the mixed number 1 (1/8) into an improper fraction: 1 (1/8) = 9/8. Now, simplify the expression: (1/4) × (3/5) ÷ (9/8). To divide by a fraction, multiply by its reciprocal: (1/4) × (3/5) × (8/9) = 24/180 = 2/15. Thus, the simplified expression is 2/15. Choice A (8/15) is incorrect because the correct answer is 2/15. Choice B (27/160) is incorrect as it is not the result of the given expression. Choice D (27/40) is incorrect as it does not match the simplified expression obtained.

4. When rounding 2678 to the nearest thousandth, which place value would be used to decide whether to round up or round down?

• A. Ten-thousandth
• B. Thousandth
• C. Hundredth
• D. Thousand

Correct answer: B

Rationale: When rounding 2678 to the nearest thousandth, you would look at the digit in the thousandth place, which is 7. To decide whether to round up or down, you consider the digit to the immediate right of the place you are rounding to. Since 7 is equal to or greater than 5, you round up. Choice A, ten-thousandth, is incorrect as we are rounding to the thousandth place. Choice C, hundredth, is not relevant as we are not rounding to that place value. Choice D, thousand, is incorrect as it is the original number being rounded, not the place value used for rounding.

5. A scientist is trying to determine how much poison will kill a rat the fastest. Which of the following statements is an example of an appropriate hypothesis?

• A. Rats that are given lots of poison seem to die quickly.
• B. Does the amount of poison affect how quickly the rat dies?
• C. The more poison a rat is given, the quicker it will die.
• D. Poison is fatal to rats.

Correct answer: C

Rationale: A valid hypothesis must be a testable statement that predicts a relationship between variables. Option C is the only statement that presents a clear cause-and-effect relationship between the amount of poison given and the time it takes for the rat to die. Option A is descriptive without predicting an outcome, option B is a question rather than a statement, and option D is a general fact about poison and rats, lacking a specific hypothesis for testing.

Similar Questions