Correct Answer: D

Rationale: To determine the highest number among 0.077, 0.777, 0.08, and 0.87, we compare the numbers. 0.87 is greater than 0.777, 0.08, and 0.077, making it the highest number. Choice A (0.077), Choice B (0.777), and Choice C (0.08) are lower numbers compared to 0.87, so they are incorrect.

Correct Answer: A

Rationale: To solve the expression 4y + 21/y when y = 3, substitute y = 3: 4 * 3 + 21 / 3 = 12 + 7 = 19. Therefore, the correct answer is 19. Choice A, '19,' is the correct result of the expression when y = 3. Choice B, '7.7,' is incorrect as the correct answer is an integer, not a decimal. Choice C, '23/3,' is incorrect as it is not the simplified integer result of the expression. Choice D, '11,' is incorrect as it does not result from the given expression when y = 3.

Correct Answer: C

Rationale: The greatest common factor (GCF) of two numbers is the largest number that divides both numbers without leaving a remainder. To find the GCF of 12 and 18, we factorize each number: 12 = 2 x 2 x 3 and 18 = 2 x 3 x 3. The common factors are 2 and 3. The GCF is the product of these common factors, which is 6. Therefore, 6 is the greatest common factor of 12 and 18. Choice A (2) and Choice B (3) are factors of both numbers but not the greatest common factor. Choice D (9) is not a factor of both 12 and 18, making it incorrect.

Correct Answer: B

Rationale: The correct answer is B: 150 kilograms. To find the total amount of feed, you need to multiply the number of bags by the weight of each bag. In this case, 3 bags * 50 kilograms each = 150 kilograms. Therefore, the farmer has a total of 150 kilograms of feed. Choice A (100 kilograms) is incorrect because it doesn't consider the total weight of all 3 bags. Choice C (200 kilograms) and Choice D (250 kilograms) are incorrect as they are miscalculations of the total weight of the feed.

Correct Answer: D

Rationale: Rationale: - The patient receives 150mg of medication every 4 hours. - To calculate how many milligrams the patient will receive in 24 hours, we need to determine how many times the medication is administered in 24 hours. - Since the medication is administered every 4 hours, there are 24 hours in a day, so the medication will be administered 24 / 4 = 6 times in 24 hours. - Therefore, the total amount of medication the patient will receive in 24 hours is 150mg x 6 = 900mg.