Correct Answer: A

Rationale: To convert pounds to kilograms, you need to multiply the number of pounds by 0.4536. Therefore, to find out how many kilograms are in 20 pounds, you would calculate 20 x 0.4536 = 9.072 kilograms, which is approximately 9 kilograms. Choice A is correct. Choice B (16 kilograms), Choice C (44 kilograms), and Choice D (3 kilograms) are all incorrect conversions of pounds to kilograms.

Correct Answer: C

Rationale: If Uri sold 28 balloons, Tommy sold 28 + 2 = 30 balloons. Since Serena sold 6 fewer balloons than Tommy, she sold 30 - 6 = 24 balloons. Therefore, Serena sold 24 balloons. Choice A, 20 balloons, is incorrect because it doesn't consider the difference in sales between Serena and Tommy. Choice B, 22 balloons, is incorrect as it doesn't account for the correct relation between Tommy and Serena's sales. Choice D, 32 balloons, is incorrect as it doesn't align with the given information about the sales differences.

Correct Answer: D

Rationale: To determine the amount of change received, you need to subtract the total cost from the amount given. $20 - $9.38 = $10.62. Therefore, he received $10.62 in change. Option A ($0.62) is incorrect as it is the difference in cents, not dollars. Option B ($5.02) is incorrect as it does not reflect the correct subtraction. Option C ($9.38) is incorrect as it represents the total cost of the purchase, not the change received.

Correct Answer: A

Rationale: The scale of 3:1 means that for every 3 centimeters in the drawing, it represents 1 centimeter in real life. If the length of the cicada in the drawing is 6 centimeters, in real life, it would be 6 x 3 = 18 centimeters long. Therefore, the actual length of the cicada in real life is 18 centimeters. Choice B, 6.3 centimeters, is incorrect because it does not account for the scale factor. Choices C and D, 4.6 centimeters and 4.2 centimeters respectively, are also incorrect as they do not consider the 3:1 scale used in the drawing.

Correct Answer: A

Rationale: To find 40% of 150, you multiply 150 by 0.40 (which represents 40% in decimal form). This calculation results in 60. Therefore, choice A, 60, is the correct answer. Choice B (65), choice C (70), and choice D (85) are incorrect as they do not reflect the accurate calculation for finding 40% of 150.