Correct Answer: A

Rationale: To convert 0.004 to a ratio, first express it as a fraction. 0.004 = 4/1000 = 1/250. Therefore, the ratio is 1:250. Choice A is the correct answer. Choices B, C, and D are incorrect ratios as they do not represent the equivalent fraction of 0.004.

Correct Answer: D

Rationale: To solve the equation 4x - 8 = 16, first, add 8 to both sides to isolate 4x: 4x = 24. Then, divide by 4 to solve for x: x = 6. Therefore, the correct answer is D. Choice A, x = 7, is incorrect as the correct solution is x = 6. Choices B and C are duplicates of choice A and are also incorrect.

Correct Answer: A

Rationale: 32 · (8\9) is the same as 32 (9\8) = 36.

Correct Answer: B

Rationale: Find a common denominator to subtract: 17 2\3 - 8 5\9 = 9 1\9.

Correct Answer: B

Rationale: To find 80% of a number, you multiply the number by 0.8. Therefore, 80% of 55 is calculated as 0.8 55 = 44. Choice A (40), choice C (39), and choice D (45) are incorrect as they do not represent the correct calculation for 80% of 55.