Correct Answer: A

Rationale: The correct answer is A: 28. To find 28% of 100, you multiply 0.28 (the decimal equivalent of 28%) by 100. This calculation results in 28. Therefore, 28% of 100 is 28. Choice B, 20, is incorrect as it represents 20% of 100. Choice C, 25, is incorrect as it represents 25% of 100. Choice D, 30, is incorrect as it represents 30% of 100.

Correct Answer: C

Rationale: To determine the pounds of cake that can be made with 40 eggs, divide the total number of eggs by the eggs needed per pound of cake: 40 eggs · 3 eggs/pound = 13 pounds of cake. Therefore, the correct answer is 13 pounds. Choice A, 12 pounds, is incorrect because it does not consider the ratio of eggs to cake. Choice B, 14 pounds, and Choice D, 15 pounds, are incorrect as they do not reflect the correct calculation based on the given ratio in the question.

Correct Answer: C

Rationale: To find the percentage of 8 in 40, divide 8 by 40 to get 0.2. Multiply this result by 100 to convert it to a percentage: 0.2 100 = 10%. Therefore, 8 is 10% of 40, making choice C the correct answer. Choices A, B, and D are incorrect percentages calculated from incorrect divisions and multiplications.

Correct Answer: B

Rationale: To convert kilometers to meters, you need to multiply the number of kilometers by 1000 since there are 1000 meters in 1 kilometer. Therefore, 5 kilometers is equal to 5 1000 = 5000 meters. Choice A (1000) is incorrect because it represents the number of meters in 1 kilometer, not 5 kilometers. Choice C (10000) is incorrect as it is the result of multiplying 10 (not 5) by 1000. Choice D (500) is incorrect as it represents half the correct conversion value.

Correct Answer: B

Rationale: To earn the same amount that Tim makes in 4 hours, Tim earns $30 per hour, totaling $120 in 4 hours. Joe earns $20 per hour, so to match Tim's earnings in 4 hours, Joe must work 2 hours more than Tim. Therefore, Joe needs to work 2 hours more than Tim to earn the same amount that Tim makes in 4 hours. Choices A, C, and D are incorrect as they do not accurately reflect the additional hours Joe needs to work compared to Tim to earn the same amount in 4 hours.