Correct Answer: B

Rationale: Given x=11, substitute into the expression: (11 + 44) / (2*11) = 55 / 22 = 2.5. Therefore, the correct answer is 2.5. Choice A (33) is incorrect as it does not represent the correct calculation. Choice C (13) is incorrect as it is not the result of the expression. Choice D (55/22) is incorrect as it is the same as the simplified form of the expression, not the answer to the calculation.

Correct Answer: B

Rationale: To take the medication 12 hours apart from the first dose at 8:00 AM, the second dose should be taken at 8:00 PM. However, to avoid disrupting sleep, it is recommended to take the second dose a bit earlier. Taking the second dose at 6:00 PM ensures that the medication is still being taken 12 hours apart while allowing for a buffer before bedtime to avoid any potential disruptions to sleep. Choice A (4:00 PM) is too early, not maintaining the 12-hour interval. Choice C (8:00 PM) aligns with the 12-hour interval but might be too close to bedtime, potentially causing sleep disruptions. Choice D (10:00 PM) is too late and exceeds the 12-hour interval.

Correct Answer: A

Rationale: If 2 workers can complete building one play set in 18 hours, it means one worker would take 36 hours to complete the same task. When the number of workers is doubled to 4, the time is halved, so 4 workers would take 18 hours to build one play set. To build 3 play sets, the total time needed would be 3 times the time for one play set, which equals 54 hours. Therefore, 4 workers can build 3 play sets in 27 hours, making choice A the correct answer. Choices B, C, and D are incorrect because they do not account for the correct relationship between the number of workers and the time required to complete the task.

Correct Answer: B

Rationale: If Janice sells 690 vacuum cleaners per year, Randy sells 8 times that amount, which is 690 x 8 = 5,520 vacuum cleaners per year. To find out how many Randy sells each month, you divide 5,520 by 12 (months), which equals 460 vacuum cleaners per month. Therefore, Randy sells 5,520 vacuum cleaners per year divided by 12 months, which equals 460 vacuum cleaners per month. Choices A, C, and D are incorrect as they do not reflect the correct calculation based on the information provided.

Correct Answer: A

Rationale: To add mixed numbers, first convert them to improper fractions. 6 3/4 = 27/4 and 8 1/6 = 49/6. Finding a common denominator, we get 27/4 + 49/6 = 81/12 + 98/12 = 179/12 = 14 & 11/12. Therefore, the correct answer is A. Choice B is incorrect as it does not simplify to the correct result. Choice C is in fraction form and not in mixed number form, making it incorrect. Choice D is not the correct sum of the given mixed numbers, so it is also incorrect.