Correct Answer: B

Rationale: To find the total cost of Susan's outfit, you need to add the prices of the dress, shoes, and accessories together. $69.99 + $39.99 + $34.67 = $144.65. Therefore, the correct total cost of her outfit is $144.65. Choice A ($139.65) is incorrect as it does not account for the full cost of all items. Choice C ($145.55) is incorrect as it includes an extra amount not part of the given prices. Choice D ($144.65) is incorrect due to a duplication of the correct answer.

Correct Answer: B

Rationale: To calculate a 30% decrease in 340 mg, you multiply 340 by 0.3, which equals 102 mg. Subtracting this from the current dosage gives 340 - 102 = 238 mg. Therefore, the correct answer is 238 mg. Choice A (70 mg) is incorrect because it represents a 70% decrease, not 30%. Choice C (270 mg) is incorrect as it does not reflect the correct calculation for a 30% decrease. Choice D (340 mg) is the initial dosage and not the reduced dosage after a 30% decrease.

Correct Answer: A

Rationale: The correct way to find the radius of a circle when given the diameter is by dividing the diameter by 2 to get the radius (Radius = Diameter · 2). When given the circumference, you need to divide the circumference by 2π to find the radius (Radius = Circumference · 2π). Choice A provides the accurate formulas for finding the radius in both scenarios. Choices B, C, and D present incorrect formulas that do not align with the correct calculations for determining the radius of a circle based on the given information.

Correct Answer: A

Rationale: The sum of two odd numbers is even because odd numbers have a difference of 1 and adding them results in a multiple of 2. The sum of two even numbers is even because even numbers are multiples of 2. When an odd number and an even number are added, the result is odd because the even number contributes an extra 1 to the sum, making it an odd number. Therefore, the correct answer is A. Choices B, C, and D have incorrect combinations of the sum of odd and even numbers.

Correct Answer: A

Rationale: The correct answer is y = 3x. By examining the table provided, we can see that for each increase of 1 in x, y increases by 3. This consistent pattern indicates that y is three times the value of x, leading to the equation y = 3x. Choices B, C, and D do not match the pattern observed in the table and are therefore incorrect.