A medication must be taken twice daily, 12 hours apart. If the first dose is at 8:00 AM, what is the most convenient time for the second dose to avoid disrupting sleep?

Correct Answer: B

Rationale: To take the medication 12 hours apart from the first dose at 8:00 AM, the second dose should be taken at 8:00 PM. However, to avoid disrupting sleep, it is recommended to take the second dose a bit earlier. Taking the second dose at 6:00 PM ensures that the medication is still being taken 12 hours apart while allowing for a buffer before bedtime to avoid any potential disruptions to sleep. Choice A (4:00 PM) is too early, not maintaining the 12-hour interval. Choice C (8:00 PM) aligns with the 12-hour interval but might be too close to bedtime, potentially causing sleep disruptions. Choice D (10:00 PM) is too late and exceeds the 12-hour interval.

Correct Answer: C

Rationale: To find the total surface area of the fountain, we first calculate the surface area of the sphere and the cylinder separately. For the sphere: - Radius = Diameter / 2 = 50 / 2 = 25 cm - Surface area of a sphere = 4πr² = 4 x π x 25² = 500π cm² For the cylinder: - Radius = Diameter / 2 = 30 / 2 = 15 cm - Surface area of a cylinder = 2πrh + 2πr² = 2 x π x 15 x 80 + 2 x π x 15² = 240π + 450π = 690π cm² Total surface area = Surface area of sphere + Surface area of cylinder = 500π + 690π = 1190π cm² ≈ 5486 sq cm. Therefore, the correct answer is C. Choice A (3142 sq cm) is incorrect as it is much smaller than the correct answer. Choices B and D are also incorrect as they do not reflect the accurate calculation of the total surface area of the fountain.

Correct Answer: B

Rationale: The normal range for potassium levels is typically considered to be between 3.5 to 5.3 mmol/L. In this case, the potassium level of 4.5 mmol/L falls within this normal range. Therefore, the correct answer is that it is within the normal range (Choice B). Choice A is incorrect as 4.5 mmol/L is not too low. Choice C is also incorrect as 4.5 mmol/L is not too high. Choice D is incorrect as the given information is sufficient to determine that the potassium level is within the normal range.

Correct Answer: C

Rationale: The greatest common factor (GCF) of two numbers is the largest number that divides both numbers without leaving a remainder. To find the GCF of 12 and 18, we factorize each number: 12 = 2 x 2 x 3 and 18 = 2 x 3 x 3. The common factors are 2 and 3. The GCF is the product of these common factors, which is 6. Therefore, 6 is the greatest common factor of 12 and 18. Choice A (2) and Choice B (3) are factors of both numbers but not the greatest common factor. Choice D (9) is not a factor of both 12 and 18, making it incorrect.