Correct Answer: A

Rationale: If 30% of a number is 18, you can find the full number by dividing 18 by 0.30 (the decimal equivalent of 30%). This calculation results in 60. Therefore, the full number is 60. Choice B (30) is the result if 30% of the number itself was calculated, not the full number. Choices C (40) and D (45) are incorrect and do not align with the given information.

Correct Answer: A

Rationale: To determine the number of floors in the building, divide the total height of the building (150 feet) by the height of each floor (12 feet). 150 feet · 12 feet per floor = 12.5 floors. Since floors cannot be in fractions, the answer is rounded down to the nearest whole number, which is 13 floors. Therefore, the correct answer is A: 13 floors. Choice B (15 floors) is incorrect because the calculation results in 12.5 floors, which should be rounded down. Choices C (10 floors) and D (18 floors) are incorrect as they do not accurately reflect the division result and rounding down process.

Correct Answer: D

Rationale: To convert 1.25 to a percentage, multiply by 100. Therefore, 1.25 equals 125%. The correct answer is D because 125% is the percentage that represents 1.25. Choices A, B, and C are incorrect. A (1250%) is 10 times greater than the correct answer, B (25%) is 100 times smaller, and C (50%) is 2 times smaller than the correct percentage equivalent of 1.25.

Correct Answer: A

Rationale: To solve the division problem, we need to remember the rule 'Dividing by a fraction is the same as multiplying by its reciprocal.' Therefore, 39 · 8 · 7/6 is equivalent to 39 · 8 6/7. Simplifying this gives (39 6) · (8 7) = 234 · 56 = 56/39. Therefore, the correct answer is A. Choices B, C, and D are incorrect as they do not correctly simplify the given division problem.

Correct Answer: A

Rationale: To convert a decimal to a percent, you multiply the decimal by 100. In this case, 0.98 100 = 98%. Therefore, the correct answer is A, which is 98%. Choice B (9%) is incorrect as it results from an error in calculation. Choice C (98) is incorrect as it lacks the percent symbol. Choice D (99%) is incorrect as it is not the equivalent percentage of 0.98.