Correct Answer: C

Rationale: To find the total surface area of the fountain, we first calculate the surface area of the sphere and the cylinder separately. For the sphere: - Radius = Diameter / 2 = 50 / 2 = 25 cm - Surface area of a sphere = 4πr² = 4 x π x 25² = 500π cm² For the cylinder: - Radius = Diameter / 2 = 30 / 2 = 15 cm - Surface area of a cylinder = 2πrh + 2πr² = 2 x π x 15 x 80 + 2 x π x 15² = 240π + 450π = 690π cm² Total surface area = Surface area of sphere + Surface area of cylinder = 500π + 690π = 1190π cm² ≈ 5486 sq cm. Therefore, the correct answer is C. Choice A (3142 sq cm) is incorrect as it is much smaller than the correct answer. Choices B and D are also incorrect as they do not reflect the accurate calculation of the total surface area of the fountain.

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: A

Rationale: To make half of the recipe that calls for 2 cups of sugar, you would need 1 cup of sugar. Choice A is correct because half of 2 cups is 1 cup. Choice B (1.5 cups) is incorrect as it is three-quarters of the original amount, not half. Choice C (2 cups) is the amount required for the full recipe, not for half. Choice D (0.5 cups) is half of 1 cup, not half of 2 cups.

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: The correct answer is A: 'Find the tallest bar in the graph.' In a bar graph, the height of each bar represents the quantity being measured. The tallest bar indicates the day with the highest number of admissions. Therefore, this is the most direct and accurate method to determine the day with the highest number of admissions. Choices B, C, and D are incorrect because comparing all bars, calculating the average, or subtracting the lowest from the highest does not directly identify the day with the highest number of admissions in a bar graph.