What is the opposite of -3?

Correct Answer: B

Rationale: The opposite of a number is the number that, when added to it, results in zero. In this case, the opposite of -3 is a number that, when added to -3, gives 0. Therefore, the opposite of -3 is 3, as -3 + 3 = 0. Choice A, -6, is incorrect because -3 + (-6) = -9, not zero. Choice C, 0, is the additive inverse of 0, not -3. Choice D, 6, is also incorrect as -3 + 6 = 3, not zero.

Correct Answer: B

Rationale: To find the result of dividing 3.44 by 0.6, you perform the division operation: 3.44 · 0.6 = 5.73. When rounded off to the nearest whole number, 5.73 becomes 6. Therefore, the correct answer is 6. Choice A is incorrect as the result is not 0. Choice C is incorrect as it is not the closest whole number to 5.73. Choice D is incorrect as it does not reflect the accurate division result.

Correct Answer: C

Rationale: To add mixed numbers, first add the whole numbers together, then add the fractions. 6 + 8 = 14. For the fractions: 3/4 + 1/6 = (18 + 4) / 24 = 22/24 = 11/12. Therefore, 6 & 3/4 + 8 & 1/6 equals 14 & 11/12. Choice A is incorrect as it does not represent the correct sum. Choice B is incorrect because it does not match the correct result. Choice D is incorrect as it simplifies to 12 & 1/6, not 12 & 3/24.

Correct Answer: C

Rationale: To convert grams to milligrams, you need to multiply by 1,000 since there are 1,000 milligrams in a gram. Therefore, 7 grams is equal to 7,000 milligrams. Choice A (700 mg) is incorrect because it represents grams to milligrams incorrectly. Choice B (0.7 mg) is incorrect as it converts grams to milligrams erroneously by decimal placement. Choice D (0.07) is incorrect as it converts grams to milligrams inaccurately by misplacing the decimal point.

Correct Answer: A

Rationale: To add fractions, find a common denominator, which in this case is 40. Convert each fraction to have the common denominator: 7/8 = 35/40, 9/10 = 36/40, and 6/5 = 48/40. Add these fractions to get 119/40. Simplify this improper fraction to a mixed number, which is 3 & 39/40. Choice B and C are incorrect as they do not represent the sum of the fractions. Choice D is incorrect; the whole number part should be 3, not 2.