Correct Answer: D

Rationale: To express the repeating decimal 0.7777... as a fraction, let x = 0.7777... Multiplying both sides by 10 to shift the decimal point to the right gives: 10x = 7.7777... Subtracting the original equation from the new equation eliminates the repeating decimal: 10x - x = 7.7777... - 0.7777... 9x = 7 x = 7/9. Therefore, the decimal 0.7777... can be expressed as the fraction 7/9. Choices A, B, and C are incorrect as they do not accurately represent the decimal 0.7777... when converted to a fraction.

Correct Answer: A

Rationale: To multiply the fractions, convert the mixed numbers to improper fractions: 1 4/5 = 9/5. Then, multiply the fractions: (4/9) (9/5) (2/5) = 8/25. The correct answer is A. Choice B is incorrect as it does not match the result of the multiplication. Choice C is incorrect as it is not the result of multiplying the fractions. Choice D is incorrect as it is not the result of the given multiplication.

Correct Answer: B

Rationale: Rationale: 1. Calculate the excess blood sugar above 100mg/dL: 180mg/dL - 100mg/dL = 80mg/dL. 2. Determine the insulin dose based on the patient's usual insulin dose: 80mg/dL / 40mg/dL = 2 units. 3. Add the calculated insulin dose to the patient's usual insulin dose: 1 unit (usual dose) + 2 units (calculated dose) = 3 units. Therefore, the correct answer is 3 units of insulin should be administered to the diabetic patient with a blood sugar level of 180mg/dL.

Correct Answer: D

Rationale: To find the result of subtracting 8.4 from 3.7, you need to subtract 3.7 from 8.4. Performing this subtraction, 8.4 - 3.7 equals 4.7. Therefore, the correct answer is 4.7. Choice A, 4.5, is incorrect as it is not the result of subtracting 8.4 from 3.7. Choices B and C, 4.8 and 4.6 respectively, are also incorrect as they do not match the correct subtraction result of 4.7.

Correct Answer: D

Rationale: To convert quarts to ounces, you need to know that 1 quart is equal to 32 ounces. Therefore, to find out how many ounces are in 2.5 quarts, you multiply 2.5 by 32, which equals 80 ounces. So, the correct answer is 80 ounces. Choice A (64 ounces) is incorrect as it miscalculates the conversion. Choice B (40 ounces) is incorrect as it does not consider the correct conversion factor. Choice C (32 ounces) is incorrect as it provides the conversion for 1 quart only, not for 2.5 quarts.