Correct Answer: A

Rationale: To find the total area covered by the stones, multiply the number of stones by the area each stone covers: 1,200 stones * 0.75 sq ft = 900 sq ft. Therefore, the stones will cover 900 sq ft, which is closest to 800 sq ft among the answer choices A, B, C, and D. The correct answer is A, 800 sq ft. Choices B, C, and D are incorrect as they do not result from the correct calculation of multiplying the number of stones by the area each stone covers.

Correct Answer: B

Rationale: To find the result of dividing 3.44 by 0.6, you perform the division operation: 3.44 · 0.6 = 5.73. When rounded off to the nearest whole number, 5.73 becomes 6. Therefore, the correct answer is 6. Choice A is incorrect as the result is not 0. Choice C is incorrect as it is not the closest whole number to 5.73. Choice D is incorrect as it does not reflect the accurate division result.

Correct Answer: A

Rationale: To add fractions, you need a common denominator. In this case, the common denominator is 57 * 75 = 4275. So, (47*75 + 65*57) / 4275 = (3525 + 3705) / 4275 = 7230 / 4275. Simplifying this fraction gives 1 23/35. Choice B: 2 1/3 is incorrect as the correct result is not a mixed number. Choice C: 1 2/3 is incorrect as it does not match the simplified result of the expression. Choice D: 1 5/6 is incorrect as it is a different value from the correct result obtained by adding the fractions.

Correct Answer: A

Rationale: To solve the equation 3x - 5 = 10, start by isolating x. Add 5 to both sides of the equation to get 3x = 15. Then, divide by 3 on both sides to find x = 5. Therefore, the correct answer is x = 5. Choice B, x = 10, is incorrect because adding 5 to 10 does not yield 10. Choice C, x = 15, is incorrect as adding 5 to 15 does not equal 10. Choice D, x = 20, is incorrect because adding 5 to 20 does not result in 10.

Correct Answer: A

Rationale: To find 20% of a number, you multiply the number by 0.20. In this case, 0.20 * 2 = 0.4. Therefore, 0.4 is 20% of 2. Choice A (0.4) is correct. Choice B (0.2) is incorrect because it represents 10% of 2, not 20%. Choice C (0.3) is incorrect as it is not the result of calculating 20% of 2. Choice D (0.1) is incorrect as it represents 5% of 2, not 20%.