Subtract 17 2\3 - 8 5\9.

Correct Answer: B

Rationale: Find a common denominator to subtract: 17 2\3 - 8 5\9 = 9 1\9.

Correct Answer: A

Rationale: To convert 0.004 to a ratio, first express it as a fraction. 0.004 = 4/1000 = 1/250. Therefore, the ratio is 1:250. Choice A is the correct answer. Choices B, C, and D are incorrect ratios as they do not represent the equivalent fraction of 0.004.

Correct Answer: A

Rationale: When adding two negative numbers, you add their absolute values and keep the negative sign. In this case, -5 + (-8) is equal to -13 because the absolute values of 5 and 8 add up to 13, and the negative sign is retained. Choice B (8) is incorrect because adding two negative numbers results in a negative sum. Choice C (13) is incorrect as it doesn't consider the negative signs of the numbers being added. Choice D (-5) is incorrect because it does not account for the addition of the two negative numbers.

Correct Answer: A

Rationale: 300 milliliters is equivalent to 0.3 liters. To convert milliliters to liters, you need to move the decimal three places to the left. Therefore, the correct answer is A. Choice B (3 liters) is incorrect as it represents the conversion of 3000 milliliters. Choice C (0.03 liters) is incorrect as it represents the conversion of 30 milliliters. Choice D (3.3 liters) is also incorrect as it is not the correct conversion of 300 milliliters.

Correct Answer: B

Rationale: To find 80% of a number, you multiply the number by 0.8. Therefore, 80% of 55 is calculated as 0.8 55 = 44. Choice A (40), choice C (39), and choice D (45) are incorrect as they do not represent the correct calculation for 80% of 55.

Correct Answer: C

Rationale: There are 32 ounces in a quart, so to find out how many ounces are in 4.5 quarts, you need to multiply 4.5 by 32. 4.5 quarts * 32 ounces/quart = 144 ounces. Therefore, the correct answer is 144 ounces. Choices A, B, and D are incorrect because they do not correctly calculate the conversion from quarts to ounces.

Correct Answer: C

Rationale: The metric system is based on powers of 10, making calculations and conversions easier because each unit increases or decreases by a factor of 10. This factor allows for a simple and consistent way to move between different units within the system. Choice A, 'The length of Napoleon's forearm' is incorrect as the metric system is not based on a physical attribute but on a standardized mathematical factor. Choice B, '2,' and Choice D, 'Atomic weight of helium,' are also incorrect as they do not align with the foundational principle of the metric system being based on powers of 10.

Correct Answer: A

Rationale: To divide mixed numbers, convert them to improper fractions and then multiply by the reciprocal of the divisor. Here, 4 7/8 = 39/8 and 1 1/6 = 7/6. Dividing 39/8 by 7/6 gives 39/8 · 7/6 = 39/8 * 6/7 = 234/56 = 4 5/28. Therefore, the correct answer is A. Choices B, C, and D are incorrect as they do not represent the correct result of dividing 4 7/8 by 1 1/6.

Correct Answer: D

Rationale: To solve the equation 4x - 8 = 16, first, add 8 to both sides to isolate 4x: 4x = 24. Then, divide by 4 to solve for x: x = 6. Therefore, the correct answer is D. Choice A, x = 7, is incorrect as the correct solution is x = 6. Choices B and C are duplicates of choice A and are also incorrect.