Correct Answer: B

Rationale: To simplify: First, subtract the whole numbers: 3 - 1 = 2. Then, subtract the fractions: (1/6) - (5/6) = - (4/6) = - (2/3). Now, subtract (2 - 2/3) = 1 (1/3).

Correct Answer: C

Rationale: To find the total amount contributed, you can add the individual contributions: $12.03 + $11.96 + $12.06 = $36. Therefore, the roommates used a total of $36 to purchase the gift. Choice A ($34), B ($35), and D ($37) are incorrect as they do not reflect the accurate total amount contributed by the roommates.

Correct Answer: D

Rationale: Joshua must answer more than 92 points' worth of questions. Since each question is worth 4 points, the inequality is 4x > 92. Choice A (4x < 30) is incorrect as it represents that Joshua must answer less than 30 questions correctly, not earning more than 92 points. Choice B (4x < 92) is incorrect as it signifies that Joshua must earn less than 92 points, which contradicts the requirement. Choice C (4x > 30) is incorrect as it implies that Joshua must answer more than 30 questions correctly, but the threshold is 92 points, not 30 points.

Correct Answer: C

Rationale: To calculate the final dosage, first find 1/5 of 310 mg, which is 62 mg, and subtract it from the original dosage. This gives 310 mg - 62 mg = 248 mg. Then, subtract an additional 20 mg from the result to get the final dosage: 248 mg - 20 mg = 228 mg. Therefore, the patient's final dosage is 228 mg. Choice A (20 mg) is incorrect because it only considers the second reduction of 20 mg and misses the initial reduction by 1/5. Choice B (42 mg) is incorrect as it miscalculates the reduction amounts. Choice D (248 mg) is incorrect as it does not account for the second reduction of 20 mg.

Correct Answer: B

Rationale: The correct answer is 13%. To find the percentage of the total staff that is certified and available to work, we first calculate the percentage of staff available, which is 100% - 35% = 65%. Then, we find the percentage of the available staff that is certified, which is 20% of 65% = 0.20 0.65 = 0.13, or 13%.