Correct Answer: A

Rationale: To solve the expression 30 1/2 - 13 3/4, first convert the mixed numbers to improper fractions. 30 1/2 is equivalent to 61/2 and 13 3/4 is equivalent to 55/4. Subtracting 55/4 from 61/2 gives 16 3/4, which is the correct answer. Choice B (17) is incorrect as the correct answer is a mixed number, not a whole number. Choice C (15 1/4) is incorrect as it doesn't result from subtracting the given fractions. Choice D (15) is incorrect; the correct answer is greater than 15.

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.

Correct Answer: B

Rationale: When multiplying a positive integer by a negative integer, the product will always be negative. This is a fundamental rule of arithmetic. The sign of the product is determined by the rule that states a positive number multiplied by a negative number results in a negative number. Therefore, the statement that the product will always be negative is always true when multiplying positive and negative integers. Choice A is incorrect because the product is not always positive when multiplying positive and negative integers. Choice C is incorrect because the product is not dependent on the specific numbers but on the signs of the integers being multiplied. Choice D is incorrect as positive and negative integers can be multiplied.

Correct Answer: A

Rationale: The nurse worked a total of 40 hours (2 x 12 hours + 2 x 8 hours) during the week. Multiplying 40 hours by her hourly rate of $22 gives a total earning of $960 for the week. Therefore, the correct answer is $960. Choice B ($1,080) is incorrect because it miscalculates the earnings by adding extra hours. Choice C ($990) is incorrect as it does not account for the correct number of hours worked. Choice D ($880) is incorrect as it underestimates the total earnings by not considering all hours worked.

Correct Answer: B

Rationale: To divide 40.3 by 4.8, you perform the calculation: 40.3 · 4.8 ≈ 8.4. Therefore, the correct answer is 8.4. Choice A (7.5) is incorrect as it is the result of dividing 40.3 by 5.4. Choice C (6.2) is incorrect as it is the result of dividing 40.3 by 6.5. Choice D (9.1) is incorrect as it is the result of dividing 40.3 by 4.4.