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: 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: The correct answer is $90. If he pays $270 per month in rent and saves a total of $360 per month, he puts $360 - $270 = $90 into his house savings account each month. Choice B ($270) is incorrect as this amount represents the rent paid, not the amount saved. Choices C ($730) and D ($810) are both significantly higher than the correct amount of $90, making them incorrect as they do not align with the given information in the question.

Correct Answer: B

Rationale: To convert decimeters to centimeters, you need to multiply by 10 since 1 decimeter is equal to 10 centimeters. Therefore, to find the width of the book in centimeters, multiply 5 decimeters by 10: 5 decimeters * 10 = 50 centimeters. This means the width of the book is 50 centimeters, making choice B, "25 centimeters," the correct answer. Choices A, C, and D are incorrect because they do not correctly convert decimeters to centimeters.

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.