Nokea
What is the volume of a ball with a diameter of 7 inches?
- A. 165.7 in³
- B. 179.6 in³
- C. 184.5 in³
- D. 192.3 in³
Correct Answer: A
Rationale: To find the volume of a sphere, the formula V = (4/3)πr³ is used, where r is the radius of the sphere. Given that the diameter of the ball is 7 inches, the radius (r) would be half of the diameter, which is 3.5 inches. Plugging this value into the formula: V = (4/3)π(3.5)³ = (4/3)π(42.875) ≈ 165.7 in³. Therefore, the correct answer is A. Choice B, C, and D are incorrect as they do not accurately represent the volume of the ball with a diameter of 7 inches.
You may also like to solve these questions
Veronica paid an additional $3,015 for a surround sound system and $5,218 for a maintenance package. What was the total price of her new car?
- A. $50,210
- B. $48,443
- C. $43,225
- D. $40,210
Correct Answer: B
Rationale: To calculate the total price of Veronica's new car, you must sum the original price of the car with the additional costs. Veronica paid $3,015 for the surround sound system and $5,218 for the maintenance package, totaling $3,015 + $5,218 = $8,233 in additional costs. Adding this to the original price of the car, $40,210, gives $40,210 + $8,233 = $48,443. Therefore, the total price of Veronica's new car is $48,443. Choice A, $50,210, is incorrect as it does not factor in the correct additional costs. Choice C, $43,225, is incorrect because it does not include the additional costs. Choice D, $40,210, is incorrect as it only represents the original price of the car without the added expenses.
Dr. Lee observed that 30% of all his patients developed an infection after taking a certain antibiotic. He further noticed that 5% of those 30% required hospitalization to recover from the infection. What percentage of Dr. Lee's patients were hospitalized after taking the antibiotic?
- A. 1.50%
- B. 5%
- C. 15%
- D. 30%
Correct Answer: C
Rationale: Out of all the patients who took the antibiotic, 30% developed an infection. Among those with infections, 5% required hospitalization. To find the percentage of all patients hospitalized, we multiply the two percentages: 30% * 5% = 1.5%. Therefore, 1.5% of all patients were hospitalized. Choice A (1.50%) is the calculated percentage of all patients hospitalized, not 1.50%. Choice B (5%) is the percentage of patients who developed an infection and required hospitalization, not all patients. Choice D (30%) represents the initial percentage of patients who developed an infection, not the percentage hospitalized.
In the winter of 2006, 6 inches of snow fell in Chicago, IL. The following winter, 3 inches of snowfall fell in Chicago. What was the percent decrease in snowfall in Chicago between those two winters?
- A. 69.40%
- B. 59.00%
- C. 41.00%
- D. 24.70%
Correct Answer: C
Rationale: To calculate the percent decrease in snowfall between the two winters, use the formula: Percent Decrease = ((Initial Value - Final Value) / Initial Value) * 100. In this case, the initial value is 6 inches and the final value is 3 inches. Plug these values into the formula: ((6 - 3) / 6) * 100 = (3 / 6) * 100 = 0.5 * 100 = 50%. Therefore, the correct answer is 50%, which is not listed among the choices provided. Among the given choices, the closest percentage is 41.00%, which corresponds to choice C.
Elijah drove 45 miles to his job in an hour and ten minutes in the morning. On the way home in the evening, however, the traffic was much heavier, and the same trip took an hour and a half. What was his average speed in miles per hour for the round trip?
- A. 30
- B. 45
- C. 36
- D. 40
Correct Answer: A
Rationale: To find the average speed for the round trip, we calculate the total distance and total time traveled. The total distance for the round trip is 45 miles each way, so 45 miles * 2 = 90 miles. The total time taken for the morning trip is 1 hour and 10 minutes (1.17 hours), and for the evening trip is 1.5 hours. Therefore, the total time for the round trip is 1.17 hours + 1.5 hours = 2.67 hours. To find the average speed, we divide the total distance by the total time: 90 miles / 2.67 hours ≈ 33.7 miles per hour. The closest option is A, 30 miles per hour, making it the correct answer. Choice B (45) is the total distance for the round trip, not the average speed. Choices C (36) and D (40) are not derived from the correct calculations and do not represent the average speed for the round trip.
Adrian measures the circumference of a circular picture frame with a radius of 3 inches. Which of the following is the best estimate for the circumference of the frame?
- A. 12 inches
- B. 16 inches
- C. 18 inches
- D. 24 inches
Correct Answer: C
Rationale: The circumference of a circle is given by the formula Circumference = 2 x π x radius. Given that the radius of the picture frame is 3 inches, the estimated circumference can be calculated as 2 x π x 3 = 18.84 inches, which is closest to 18 inches among the given options. Choice A (12 inches) is too small, choice B (16 inches) is also underestimated, and choice D (24 inches) is too large based on the calculated value using the formula.