Correct Answer: B

Rationale: To find the least number of computers that must be shipped and sold so that the amount received is at least equal to the shipping cost, we set up the inequality 400x >= 3000 + 100x. Simplifying this inequality gives 300x >= 3000, and dividing by 300 results in x >= 10. Therefore, at least 15 computers must be shipped and sold to cover the shipping cost, making choice B the correct answer. Choices A, C, and D are incorrect as they represent numbers less than 15, which would not cover the shipping cost.

Correct Answer: C

Rationale: To find the amount of blood used for further tests, we multiply 500 mL by 0.1666 (equivalent to 16.66%). This calculation results in 83.3, which rounded to the nearest hundredth is 83.33. Therefore, 83.33 milliliters of blood were used for further tests. Choice A is incorrect as it does not consider rounding to the nearest hundredth. Choices B and D are slightly off due to incorrect rounding. Choice C is the correct answer after rounding to the nearest hundredth.

Correct Answer: B

Rationale: To calculate the amount spent on employee wages and benefits, we need to find two-thirds (2/3) of the total operating expenses of $130,000. This equals $86,666.67, which is the correct answer. Choice A ($43,333.33) is incorrect as it represents one-third of the total expenses. Choice C ($52,000.00) and Choice D ($78,000.00) are also incorrect as they do not correspond to two-thirds of the total operating expenses.

Correct Answer: A

Rationale: To find the actual distance in miles, you need to set up a proportion using the scale provided (1 inch = 45 miles). Since the distance on the map is 3.2 inches, you can set up the proportion: 1 inch / 45 miles = 3.2 inches / x miles. Cross-multiply to solve for x: 1 * x = 45 * 3.2, x = 144. Therefore, the actual distance in miles is 144. Choices B, C, and D are incorrect because they do not accurately calculate the actual distance using the scale provided.

Correct Answer: C

Rationale: When 35% is deducted for taxes and 4% for insurance, the total percentage taken out of the paycheck is 35% + 4% = 39%. Therefore, the correct answer is 39%, which corresponds to option C. Option A (20%) is incorrect because it does not account for the total deductions. Option B (31%) is incorrect as it does not sum up the percentages correctly. Option D (42%) is incorrect as it overestimates the total deductions.