Nursing Elites

1. In Mrs. McConnell's classroom, there are 5 students with hazel eyes and 2 students with green eyes out of a total of 30 students. What percentage of the students have either hazel or green eyes?

• A. 0.23
• B. 0.3
• C. 0.47
• D. 0.77

Correct answer: A

Rationale: To calculate the percentage of students with either hazel or green eyes, add the number of students with hazel and green eyes (5 + 2 = 7) and divide by the total number of students (30): 7 ÷ 30 ≈ 0.23 or 23%. The correct answer is A, 0.23, which represents 23% of the total students. Choice B, 0.3, is incorrect as it corresponds to 30%, which is higher than the total number of students. Choice C, 0.47, is incorrect as it represents 47%, which is also higher than the total number of students. Choice D, 0.77, is incorrect as it corresponds to 77%, which is much higher than the total number of students.

2. 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.

3. What is the median of the data set below: 5, -3, 10, -2, 0?

• A. 10
• B. 0
• C. 5
• D. 2

Correct answer: B

Rationale: To find the median, we first need to arrange the data set in ascending order: -3, -2, 0, 5, 10. The median is the middle value in the ordered set. As there are 5 numbers, the middle value is the third number, which is 0. Therefore, the correct answer is 0. Choice A (10) and Choice D (2) are not correct because they are not the middle values once the data set is ordered. Choice C (5) is also incorrect as it is not the middle value in the ordered data set.

4. Which of the following statements demonstrates a negative correlation between two variables?

• A. People who play baseball more tend to have more hits
• B. Shorter people tend to weigh less than taller people
• C. Tennis balls that are older tend to have less bounce
• D. Cars that are older tend to have higher mileage

Correct answer: C

Rationale: The correct answer is C. This statement demonstrates a negative correlation between two variables as it indicates that as tennis balls age, their bounce tends to decrease. In a negative correlation, as one variable increases, the other tends to decrease. Choices A, B, and D do not illustrate a negative correlation. Choice A describes a positive correlation, as playing baseball more is associated with having more hits. Choice B does not show a correlation but a general observation. Choice D also does not demonstrate a correlation; it simply states that older cars tend to have higher mileage, without implying a relationship between age and mileage.

5. Which of the following relationships represents no correlation between two variables?

• A. As a student’s class attendance decreases, the student’s overall grade remains the same
• B. As the number of hours a person exercises decreases, the weight of that person increases
• C. As the number of miles driven increases, the amount of gasoline in the tank decreases
• D. As the amount of water a plant receives increases, the growth rate of the plant increases

Correct answer: A

Rationale: Choice A represents no correlation between two variables as it states that as a student’s class attendance decreases, the student’s overall grade remains the same. This scenario shows no relationship between class attendance and grade. In contrast, choices B, C, and D show clear correlations between the variables mentioned. Choice B indicates a negative correlation between exercise hours and weight gain, choice C indicates a negative correlation between miles driven and gasoline in the tank, and choice D indicates a positive correlation between water intake and plant growth rate, making them all examples of correlated relationships.

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