Correct Answer: C

Rationale: The correct answer is C: Early afternoon to bedtime. The healthcare professional's work hours from 1300 to 2000 correspond to 1 PM to 8 PM, indicating work during the afternoon and early evening. Choice A (Early morning to early afternoon) is incorrect because the professional works in the afternoon and early evening, not the morning. Choice B (Lunchtime to midnight) is incorrect as the professional finishes work before midnight, not until midnight. Choice D (Midnight to sunrise) is incorrect as the professional's work hours are during the daytime and evening, not overnight.

Correct Answer: A

Rationale: The correct answer is A: 1,760. According to the standard distance conversion, there are 1,760 yards in a mile. This conversion is widely accepted and used in various fields. Choice B, 1,700, is incorrect as it does not correspond to the standard conversion. Choice C, 1,800, represents a different value and is therefore incorrect. Choice D, 1,750, is not the accurate conversion for yards in a mile and is incorrect.

Correct Answer: B

Rationale: To find the total staff working that day, add up all the staff members: 25 registered nurses + 75 unlicensed assistants + 5 phlebotomists + 6 receptionists + 45 physicians = 156 staff members. Since the staff was at 68% strength, multiply 156 by 0.68 to get 106. Therefore, approximately 106 people were working that day. Choice A, 102, is incorrect because it underestimates the total staff. Choice C, 98, is incorrect because it is too low. Choice D, 110, is incorrect because it overestimates the total staff.

Correct Answer: C

Rationale: To find the flow rate in drops per minute, first, calculate the total volume in drops by multiplying the volume in milliliters by the number of drops per milliliter (500ml * 20 drops/ml = 10,000 drops). Then, divide this total number of drops by the infusion time in minutes (4 hours * 60 minutes/hour = 240 minutes) to get the flow rate. Therefore, the correct flow rate is 50 drops/min. Choice A is incorrect because it miscalculates the flow rate. Choice B is incorrect as it also miscalculates the flow rate. Choice D is incorrect as it overestimates the flow rate.

Correct Answer: D

Rationale: A perfect square is a number obtained by squaring an integer. In this case, 16 is a perfect square because it is the result of squaring 4 (4 x 4 = 16). The other answer choices, 10, 12, and 15, are not the product of squaring any whole number, making them incorrect. Therefore, the correct answer is 16, as it is a perfect square.