In a fraction, which number is the numerator and which is the denominator?

Correct Answer: A

Rationale: The correct answer is A: 'Numerator: top, Denominator: bottom.' In a fraction, the numerator is the top number, representing the part of the whole being considered, while the denominator is the bottom number, indicating the total number of equal parts into which the whole is divided. Choices B, C, and D are incorrect because they provide inaccurate descriptions of the numerator and denominator positions in a fraction.

Correct Answer: A

Rationale: The correct answer is A: PEMDAS. PEMDAS stands for the order of operations: Parentheses, Exponents, Multiplication and Division (left to right), Addition and Subtraction (left to right). It is a fundamental rule to follow in mathematics to ensure calculations are done correctly. Choices B, C, and D are incorrect as they do not encompass the essential rule that PEMDAS provides for solving mathematical expressions.

Correct Answer: C

Rationale: The correct answer is C. A rational number can be a whole number, fraction, or decimal. A rational number is any number that can be expressed as a ratio of two integers (where the denominator is not zero), which includes whole numbers, fractions, and decimals. Choice A is incorrect because rational numbers are not limited to being whole numbers. Choice B is incorrect because a rational number can be a fraction, decimal, or whole number. Choice D is incorrect because rational numbers can definitely be decimals, as long as the decimal representation is either terminating or repeating.

Correct Answer: C

Rationale: The least common denominator of two fractions is the least common multiple of both denominators. This is because the least common denominator is the smallest number that both denominators can divide into evenly, ensuring that both fractions can be expressed with a common denominator. Choice A is incorrect as the least common denominator is a multiple of both denominators, not a number that multiplies into both. Choice B is incorrect because the common denominator needs to be a multiple of both denominators, not just a number they can divide into evenly. Choice D is incorrect as the greatest common factor is not used to find the least common denominator, but rather the least common multiple.

Correct Answer: B

Rationale: Histograms are specifically designed to display the frequency distribution of continuous data, showing the distribution of values over intervals or bins. On the other hand, bar graphs are used to compare different categories or discrete data points. Therefore, the correct answer is B. Choices A, C, and D are incorrect because histograms are not primarily used for comparing categories, percentages, or proportions, but rather for visualizing the distribution of frequencies within data intervals.