Correct Answer: A

Rationale: To find x, we set up the proportion 15:x = 3:8. Cross multiply to get 15*8 = 3*x, which simplifies to 120 = 3x. Dividing by 3 on both sides gives x = 40. Therefore, x=40 is the correct answer. Choices B, C, and D are incorrect because they do not match the correct calculation. Option B results from incorrectly dividing 15 by 3 instead of multiplying it by 8. Option C comes from dividing 15 by 3, and Option D is the result of dividing 15 by 8 instead of multiplying by 3.

Correct Answer: A

Rationale: To convert the blood glucose level from millimoles per liter (mmol/L) to milligrams per deciliter (mg/dL), we need to perform a double conversion. 1 millimole is equivalent to 180.15 milligrams, and 1 liter is equal to 10 deciliters. First, multiply the glucose level (5.5 mmol/L) by the conversion factor for millimoles to milligrams (180.15 mg/mmol), then divide by the conversion factor for liters to deciliters (10 dL/L): 5.5 mmol/L * 180.15 mg/mmol / 10 dL/L ≈ 55 mg/dL. Therefore, the equivalent blood glucose level in mg/dL is 55. Choice A is correct. Choice B is incorrect as it does not account for the conversion factors properly. Choices C and D are significantly off as they do not follow the correct conversion calculations.

Correct Answer: C

Rationale: To find the result of dividing 0.9 by 3, we perform the division operation, which equals 0.3. Therefore, the correct answer is 0.3. Choice A (0) is incorrect as the result is not zero, but 0.3. Choice B (3) is incorrect as 0.9 divided by 3 is not 3 but 0.3. Choice D (9) is incorrect as 0.9 divided by 3 is not 9 but 0.3.

Correct Answer: C

Rationale: To find the volume of a hemispherical bowl, we use half the formula for a sphere's volume: (2/3) * π * (radius)^3. Given the diameter is 30cm, the radius is half of that, which is 15cm. Substitute the radius into the formula: (2/3) * π * (15cm)^3 ≈ 2700 cu cm. Therefore, the correct volume is approximately 2700 cu cm. Choices A, B, and D are incorrect as they do not correctly calculate the volume of the hemispherical bowl.

Correct Answer: A

Rationale: To convert fluid ounces to gallons, you need to know that there are 128 fluid ounces in a gallon. To find how many gallons are in 576 fluid ounces, divide 576 by 128, which equals 4.5 gallons. Since we are looking for the closest whole number, the answer is 4 gallons. Choice A is correct. Choice B, C, and D are incorrect as they do not accurately represent the conversion from fluid ounces to gallons.