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: C

Rationale: To calculate the percent decrease in snowfall between the two winters, use the formula: Percent Decrease = ((Initial Value - Final Value) / Initial Value) * 100. In this case, the initial value is 6 inches and the final value is 3 inches. Plug these values into the formula: ((6 - 3) / 6) * 100 = (3 / 6) * 100 = 0.5 * 100 = 50%. Therefore, the correct answer is 50%, which is not listed among the choices provided. Among the given choices, the closest percentage is 41.00%, which corresponds to choice C.

Correct Answer: B

Rationale: Each container of chicken broth contains 410 milliliters. Jennifer added four containers, which totals 4 * 410 = 1640 milliliters of chicken broth. She then added 1 liter of water, equivalent to 1000 milliliters. Combining all the liquids, we get 1640 + 1000 = 2640 milliliters, which equals 2.64 liters. Choice A is incorrect because it miscalculates the total liquid volume. Choice C is incorrect as it greatly overestimates the liquid amount. Choice D is incorrect as it also overestimates the liquid content in the pot.

Correct Answer: A

Rationale: To simplify the given expression 5x - 2y + 4x + y, we combine like terms. Grouping the x terms together and the y terms together, we have 5x + 4x - 2y + y. Combining like terms results in 9x - y. Therefore, the simplest form of the expression is 9x - y, which corresponds to option A. Option B is incorrect because it incorrectly subtracts 3y instead of just y. Option C is incorrect because it adds 3y instead of subtracting y. Option D is incorrect as it separates x and y with a semicolon instead of an operation, providing no simplified expression.

Correct Answer: A

Rationale: To find the average speed for the round trip, we calculate the total distance and total time traveled. The total distance for the round trip is 45 miles each way, so 45 miles * 2 = 90 miles. The total time taken for the morning trip is 1 hour and 10 minutes (1.17 hours), and for the evening trip is 1.5 hours. Therefore, the total time for the round trip is 1.17 hours + 1.5 hours = 2.67 hours. To find the average speed, we divide the total distance by the total time: 90 miles / 2.67 hours ≈ 33.7 miles per hour. The closest option is A, 30 miles per hour, making it the correct answer. Choice B (45) is the total distance for the round trip, not the average speed. Choices C (36) and D (40) are not derived from the correct calculations and do not represent the average speed for the round trip.