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: 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: 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.

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.

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.