Nokea
Solve for y if y = 3: 4y + 21/y
- A. 19
- B. 7.7
- C. 23/3
- D. 11
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.
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A marathon runner completes 21.6 miles and burns 2,274 calories. What is the rate of calories burned per mile?
- A. 105.28
- B. 105.37
- C. 105.45
- D. 105.55
Correct Answer: A
Rationale: To find the rate of calories burned per mile, you divide the total calories burned by the total miles run: 2274 calories / 21.6 miles = 105.28 calories per mile. Therefore, the correct answer is A. Choices B, C, and D are incorrect as they do not match the calculated value. The rate of calories burned per mile is a precise calculation based on the given values, and only choice A aligns with the correct calculation.
What is the perimeter of a square with a side length of 5 meters?
- A. 15 meters
- B. 20 meters
- C. 25 meters
- D. 30 meters
Correct Answer: B
Rationale: The formula to calculate the perimeter of a square is P = 4s, where P is the perimeter and s is the length of a side. Given that the side length is 5 meters, the perimeter is 4 * 5 = 20 meters. Therefore, the correct answer is B. Choices A (15 meters), C (25 meters), and D (30 meters) are incorrect as they do not correctly apply the formula to calculate the perimeter of a square.
An artist sells paintings at $5.50 each. She has 7 stands and pays $35 per stand. What is her profit if she sells an average of 11 paintings per stand?
- A. $245
- B. $178.50
- C. $175
- D. $423.50
Correct Answer: B
Rationale: To calculate the profit, first determine the total revenue: 7 stands * 11 paintings per stand * $5.50 per painting = $423.50. Then, subtract the total stand expenses ($35 per stand * 7 stands = $245) from the total revenue to get the profit: $423.50 - $245 = $178.50. Therefore, the correct answer is $178.50. Option A is incorrect because it does not account for the stand expenses. Option C is incorrect as it does not consider the total revenue. Option D is incorrect as it overestimates the profit by not deducting the stand expenses.
Which number is the highest among 0.077, 0.777, 0.08, and 0.87?
- A. 0.077
- B. 0.777
- C. 0.08
- D. 0.87
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.
A water fountain has a spherical base with a diameter of 50cm and a cylindrical body with a diameter of 30cm and a height of 80cm. What is the total surface area of the fountain (excluding the water surface)?
- A. 3142 sq cm
- B. 4712 sq cm
- C. 5486 sq cm
- D. 7957 sq cm
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.