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: 32 · (8\9) is the same as 32 (9\8) = 36.

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: A

Rationale: To find 25% of a number, you multiply the number by 0.25. So, to calculate 25% of 200, you do 0.25 200 = 50. Therefore, the correct answer is A. Choice B (60) is incorrect as it is the result of calculating 30% of 200. Choice C (25) is incorrect as it represents 12.5% of 200. Choice D (30) is incorrect as it is the result of calculating 15% of 200.

Correct Answer: C

Rationale: Rationale: - The imaginary unit, denoted as "i," is defined as the square root of -1. - Therefore, 5i can be expressed as 5 times the square root of -1, which is equivalent to 5√-1. - Option A, -5, is a real number and not an imaginary unit multiple. - Option B, i^5, is equal to i because i raised to any power that is a multiple of 4 results in 1, and i^5 is equivalent to i. - Option D, 1/5i, is the reciprocal of 5i and not equivalent to 5i.

Correct Answer: B

Rationale: There are 1,000 milliliters in a liter. To convert milliliters to liters, you divide by 1,000. Therefore, 8,000 milliliters · 1,000 = 8 liters. This makes option B the correct answer. Option A, 0.8 liters, is incorrect as it is 1/10th of the correct answer. Option C, 0.8 liters (repeated), is also incorrect. Option D, 0.08 liters, is incorrect as it is 1/100th of the correct answer.

Correct Answer: A

Rationale: To determine the largest fraction, it's helpful to convert them to decimals for easier comparison. Converting the fractions to decimals gives: 3/8 = 0.375, 3/9 = 0.333, 3/6 = 0.5, and 3/7 ≈ 0.429. Therefore, 3/7 is the largest fraction among the given options. Choice B, 3/6, is actually equivalent to 3/6 = 0.5 which is greater than 3/7. Choices C and D are smaller fractions compared to 3/7, making them incorrect.

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: 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.