Ratio and proportion: 6:10=24:x

Correct Answer: A

Rationale: To solve for x, use cross-multiplication: 6x = 10 x 24 6x = 240 Now, divide both sides by 6 to find x: x = 240 / 6 = 40 Therefore, the correct answer is A. 40. Choice B, 25, is incorrect because it does not satisfy the proportion. Choice C, 240, is incorrect because it represents the value that is given in the proportion and not the value of x. Choice D, 4, is incorrect as it does not align with the correct calculation for x.

Correct Answer: A

Rationale: To solve the proportion x/250 = 3/500, cross multiply to get 500x = 750. Then solve for x by dividing both sides by 500, which results in x = 1.5. Therefore, the correct answer is A. Choice B (2) is incorrect because the correct solution is 1.5, not 2. Choice C (1500) is incorrect as it does not align with the correct calculation of the proportion. Choice D (25) is incorrect and does not match the correct solution obtained by solving the proportion.

Correct Answer: A

Rationale: To compare, convert both to decimals or percentages: Sally ate 3/5, which is 0.6 or 60%. John ate 75%. Since 75% is greater than 60%, John ate more than Sally. Thus, the correct answer is A. John. Choice B is incorrect because Sally ate a smaller percentage of her lunch compared to John. Choice C is incorrect as the percentages consumed are different. Choice D is incorrect as one of them ate more.

Correct Answer: D

Rationale: First, find how many eggs 1 chicken can produce in 24 hours. If 2 chickens produce 6 eggs: 6 eggs / 2 chickens = 3 eggs per chicken. To produce 24 eggs, we divide the required number of eggs by the production rate per chicken: 24 eggs / 3 eggs per chicken = 8 chickens. Therefore, the correct answer is D. 8 chickens. Choice A, 12 chickens, is incorrect because it does not consider the production rate per chicken. Choice B, 4 chickens, is incorrect as it does not account for the number of eggs needed. Choice C, 3 chickens, is incorrect because it miscalculates the production rate per chicken.

Correct Answer: A

Rationale: To determine the number of cakes needed, calculate the total number of people, which is 70 students + 3 staff = 73 people. Since each cake serves 24 people, divide the total number of people by 24 to get approximately 3.04. You cannot have a fraction of a cake, so round up to the next whole number, which is 4. Therefore, you need 4 cakes to serve the class of 70 students and 3 staff members. Choice B (2) is incorrect because 2 cakes would not be enough to serve 73 people. Choice C (5) is incorrect as it would be an excess of cakes. Choice D (3) is incorrect because 3 cakes would not be sufficient to serve 73 people.