Kyle has $950 in savings and wishes to donate one-fifth of it to 8 local charities. He estimates that he will donate around $30 to each charity. Which of the following correctly describes the reasonableness of his estimate?

Correct Answer: C

Rationale: Kyle initially had $950 in savings, and one-fifth of that amount would be $190. Since he wishes to donate around $30 to each charity, the total amount he would donate to 8 local charities would be $30 x 8 = $240. This amount is more than one-fifth of $1,000, making the estimate not reasonable. Choice A is incorrect because $190 is the correct one-fifth of $950, not $900. Choice B is incorrect as it compares $190 to a different amount ($1,000) rather than the actual total. Choice D is incorrect as it states that $240 is one-fifth of $1,000, which is inaccurate.

Correct Answer: C

Rationale: To find the amount of blood used for further tests, we multiply 500 mL by 0.1666 (equivalent to 16.66%). This calculation results in 83.3, which rounded to the nearest hundredth is 83.33. Therefore, 83.33 milliliters of blood were used for further tests. Choice A is incorrect as it does not consider rounding to the nearest hundredth. Choices B and D are slightly off due to incorrect rounding. Choice C is the correct answer after rounding to the nearest hundredth.

Correct Answer: A

Rationale: In the given situation, Courtney charges a $12 fee plus $2 per hour to babysit, represented by the equation: 12 + 2h where h is the number of hours. Kendra charges a $10 fee plus $5 per hour, represented by the equation: 10 + 5h. To find the number of hours for which the two charges are equal, we set the two equations equal to each other: 12 + 2h = 10 + 5h. Solving for h gives h = 2. This means that the charges are equal after 2 hours of babysitting. Choice B is incorrect because the fee and hourly rates for Courtney and Kendra are reversed, leading to an incorrect equation. Choices C and D are incorrect as they do not accurately represent the given scenario of fees and hourly rates for babysitting by Courtney and Kendra.

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.

Correct Answer: A

Rationale: The mean is the average of a set of numbers, while the median is the middle value when the numbers are arranged in order. If a set of numbers is skewed to one side with some outliers, the mean can be influenced by these extreme values, causing it to be greater or less than the median. In cases of skewed distribution, the mean typically shifts towards the direction of the outliers, making it less than the median. Choice B is incorrect because the mode, which is the most frequent number in a dataset, may or may not be greater than the median. Choice C is incorrect because the mode can be greater than the mean or median, depending on the data. Choice D is incorrect because the mode, representing the most frequent value, has no direct relationship with the range, which is the difference between the highest and lowest values in a dataset.

Correct Answer: B

Rationale: If the man chooses the financing plan, he pays $1000 as a down payment initially. Over the two-year period, he will be paying $120 per month for a total of 24 months, which amounts to $120 x 24 = $2880. Therefore, the total amount he pays for the furniture through the financing plan is $1000 (down payment) + $2880 (monthly payments) = $3880. Comparing this total with the entire amount paid in one payment with cash would be $3880 - $3000 = $880 more. So, the man would pay $880 more if he chooses the financing plan. Therefore, the correct answer is $1280 more, not $1480, $1600, or $2480. These amounts do not accurately represent the additional cost incurred by choosing the financing plan.

Correct Answer: C

Rationale: To determine how many prizes should be awarded to 5th-grade students, we need to set up the proportion of the number of 5th-grade students to the total number of students in the school. The total number of students is 35 + 38 + 38 + 33 + 36 = 180 students. To find the proportion of 5th-grade students, it would be 36/180 = 0.2. Since there are 20 prizes to be awarded, multiplying 0.2 by 20 gives us 4, which means 4 prizes should go to the 5th-grade students. Therefore, the correct answer is 4. Choice A (5) is incorrect as it does not align with the proportional distribution. Choice B (4) is the correct answer, as calculated. Choice C (7) is incorrect as it exceeds the total number of prizes available. Choice D (3) is incorrect as it does not match the proportional distribution based on the number of students.

Correct Answer: B

Rationale: If 1 inch on the map represents 60 ft, then for 10 inches on the map, the actual distance would be 10 inches x 60 ft = 600 ft. To convert this to yards, we know that 1 yard equals 3 feet. Therefore, the distance between the two points is 600 ft / 3 ft/yard = 200 yards. Choice A (1800) is incorrect because it incorrectly multiplies by 10 again instead of converting to yards. Choice C (200) is incorrect because it fails to adjust the measurement from feet to yards. Choice D (2) is incorrect as it does not consider the correct conversion factor from feet to yards.

Correct Answer: A

Rationale: To simplify the given expression 5x - 2y + 4x + y, we combine like terms. Grouping the x terms together and the y terms together, we have 5x + 4x - 2y + y. Combining like terms results in 9x - y. Therefore, the simplest form of the expression is 9x - y, which corresponds to option A. Option B is incorrect because it incorrectly subtracts 3y instead of just y. Option C is incorrect because it adds 3y instead of subtracting y. Option D is incorrect as it separates x and y with a semicolon instead of an operation, providing no simplified expression.