Solve for x: 2x + 4 = x - 6
- A. x = -12
- B. x = 10
- C. x = -16
- D. x = -10
Correct Answer: D
Rationale: To solve the equation 2x + 4 = x - 6, first, subtract x from both sides to get x + 4 = -6. Then, subtract 4 from both sides to isolate x, resulting in x = -10. Therefore, the correct answer is x = -10. Choice A is incorrect as it does not follow the correct steps of solving the equation. Choice B is incorrect as it is the result of combining x terms incorrectly. Choice C is incorrect as it is not the correct result of solving the equation step by step.
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In a study measuring the average hours worked per week by different types of hospital staff (such as nurses and physicians), what are the dependent and independent variables?
- A. The dependent variable is Nurses. The independent variable is Physicians.
- B. The dependent variable is Physicians. The independent variable is Nurses.
- C. The dependent variable is Hospital Staff. The independent variable is Average hours worked per week.
- D. The dependent variable is Average hours worked per week. The independent variable is Hospital Staff.
Correct Answer: D
Rationale: In this study, the dependent variable is the 'Average hours worked per week,' as it relies on the different types of 'Hospital Staff' (the independent variable). The amount of time worked per week varies based on the category of staff being considered. Therefore, the correct choice is D. Choices A and B incorrectly assign the dependent and independent variables to specific staff categories (Nurses and Physicians), which are actually different elements within the study. Choice C incorrectly defines the dependent variable as 'Hospital Staff,' when in fact, it is the 'Average hours worked per week' that is dependent on the type of staff.
There are 80 mg in 0.8 mL of Acetaminophen Concentrated Infant Drops. If the proper dosage for a four-year-old child is 240 mg, how many milliliters should the child receive?
- A. 0.8 mL
- B. 1.6 mL
- C. 2.4 mL
- D. 3.2 mL
Correct Answer: C
Rationale: To find out how many milliliters the child should receive, divide the total required dosage of 240 mg by the concentration of the medication, which is 80 mg per 0.8 mL. 240 mg · 80 mg/mL = 3 mL. Since each dose is 0.8 mL, the total dosage for the child would be 3 doses x 0.8 mL per dose = 2.4 mL. Therefore, the correct answer is 2.4 mL. Choice A (0.8 mL) is the concentration of the medication, not the total dose. Choices B (1.6 mL) and D (3.2 mL) are incorrect calculations that do not consider the concentration of the medication and the total required dosage correctly.
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.
What is the probability of flipping a coin and getting heads?
- A. 1/2
- B. 1/3
- C. 1/4
- D. 1/5
Correct Answer: A
Rationale: The correct answer is A: 1/2. When flipping a fair coin, there are two possible outcomes: heads or tails. The probability of getting heads is 1 out of 2 possible outcomes, which can be expressed as 1/2. Choice B, 1/3, is incorrect because a fair coin only has two sides. Choices C and D, 1/4 and 1/5, are also incorrect as they do not represent the correct probability of getting heads when flipping a coin.
If Hannah spends at least $16 on 4 packages of coffee, which of the following inequalities represents the possible costs?
- A. 16 ≥ 4p
- B. 16 < 4p
- C. 16 > 4p
- D. 16 ≤ 4p
Correct Answer: D
Rationale: To represent the relationship between the number of packages of coffee and the minimum cost, the inequality can be written as 4p ≥ 16 (cost is at least $16). This inequality can also be expressed as 16 ≤ 4p, which reads as the cost being less than or equal to $16. Therefore, the correct answer is D. Choice A (16 ≥ 4p) implies that the cost can be greater than or equal to $16, which does not align with the statement that Hannah spends at least $16. Choice B (16 < 4p) suggests that the cost is less than $16, which contradicts the given information. Choice C (16 > 4p) indicates that the cost is greater than $16, which is not accurate based on the scenario provided.