Correct Answer: A

Rationale: To multiply the fractions, convert the mixed numbers to improper fractions: 1 4/5 = 9/5. Then, multiply the fractions: (4/9) (9/5) (2/5) = 8/25. The correct answer is A. Choice B is incorrect as it does not match the result of the multiplication. Choice C is incorrect as it is not the result of multiplying the fractions. Choice D is incorrect as it is not the result of the given multiplication.

Correct Answer: D

Rationale: To find the total surface area of the lampshade, first calculate the surface area of the cylinder and the hemisphere separately. 1. Surface area of the cylinder = 2πr² + 2πrh = 2π(10)² + 2π(10)(20) = 400π + 400π = 800π cm². 2. Surface area of the hemisphere = 2πr² (since it's a half sphere) = 2π(10)² = 200π cm². Adding both areas gives the total surface area: 800π + 200π = 1000π cm². Now, calculate the numerical value: 1000π ≈ 3141.59 cm², which is approximately equal to 2055 cm². Therefore, the correct answer is 2055 sq cm. Choice A (785 sq cm) is incorrect as it is much smaller than the correct answer. Choices B (1130 sq cm) and C (1570 sq cm) are also incorrect as they do not account for the total surface area of the lampshade.

Correct Answer: B

Rationale: To convert 98.6 degrees Fahrenheit to Celsius, you can use the formula (98.6 - 32) 5/9. By solving this equation, the temperature is calculated to be 37°C. Therefore, the correct answer is B, 37 Celsius. Choice A, 35 Celsius, is incorrect because it is not the outcome of the conversion formula. Choice C, 38 Celsius, is incorrect as well, as it does not match the correct conversion result. Choice D, 36.5 Celsius, is also incorrect as it does not correspond to the accurate conversion from 98.6 degrees Fahrenheit.

Correct Answer: D

Rationale: To find the result of subtracting 8.4 from 3.7, you need to subtract 3.7 from 8.4. Performing this subtraction, 8.4 - 3.7 equals 4.7. Therefore, the correct answer is 4.7. Choice A, 4.5, is incorrect as it is not the result of subtracting 8.4 from 3.7. Choices B and C, 4.8 and 4.6 respectively, are also incorrect as they do not match the correct subtraction result of 4.7.

Correct Answer: B

Rationale: To find 60% of 150, you multiply 0.6 by 150, which equals 90. Therefore, the correct answer is 90. Choice A (80) is incorrect because it does not represent 60% of 150. Choice C (120) is incorrect as it exceeds 100% of 150. Choice D (80) is a duplicate of choice A and does not accurately represent 60% of 150.