Correct Answer: A

Rationale: When dividing fractions, you multiply by the reciprocal of the divisor. To divide 5 3/4 by 1/2, you multiply 5 3/4 by 2/1 (reciprocal of 1/2) to get 23/4 * 2/1 = 46/4 = 11 1/2. Therefore, the correct answer is A. Choice B (2 & 3/8) is incorrect as it does not result from dividing 5 3/4 by 1/2. Choice C (3 & 1/8) is incorrect as well. Choice D (18) is not the correct result of the division performed.

Correct Answer: A

Rationale: To add mixed numbers, convert them to improper fractions: 6 3/4 = 27/4 and 8 1/6 = 49/6. Then, add the fractions to get 27/4 + 49/6 = 162/24 + 98/24 = 260/24 = 21 20/24 = 21 10/12 = 21 5/6 = 14 11/12. Therefore, the correct answer is 14 11/12. Choice B (12 3/4) is incorrect as it does not match the correct calculation. Choice C (12 3/24) is incorrect due to the erroneous denominator in the final fraction. Choice D (14 2/5) is incorrect as it does not correspond to the correct sum of the fractions.

Correct Answer: C

Rationale: The nurse works from 1300 to 2000, which is a 7-hour period. To calculate the hours worked, subtract the start time from the end time: 2000 - 1300 = 700, which is equal to 7 hours. Choice A, 8 hours, is incorrect as it does not reflect the actual duration. Choice B, 11 hours, is incorrect as it overestimates the hours worked. Choice D, 12 hours, is incorrect as it is also an overestimation of the hours worked.

Correct Answer: B

Rationale: To express 0.75 as a fraction, we write it as 75/100. Simplifying this fraction by dividing both the numerator and denominator by 25 gives us 3/4. Therefore, 0.75 is equivalent to 3/4. Choice A (4/5), Choice C (1/2), and Choice D (1/4) are incorrect fractions and do not represent 0.75.

Correct Answer: D

Rationale: To convert kilograms to grams, you multiply by 1,000 since there are 1,000 grams in a kilogram. Therefore, 8 kilograms = 8 x 1,000 = 8,000 grams. The correct answer is 8,000 grams, which is option D. Choices A and C are incorrect as they incorrectly multiply by 10,000 instead of 1,000. Choice B is incorrect as it divides 8 by 10 instead of multiplying by 1,000.