What is a direct proportion? What is an inverse proportion?

Correct Answer: A

Rationale: In a direct proportion, both quantities increase or decrease together. This means that as one quantity goes up, the other also goes up, and vice versa. On the other hand, in an inverse proportion, when one quantity increases, the other decreases by the same factor. Therefore, choice A is correct as it accurately defines direct and inverse proportions. Choices B, C, and D are incorrect because they do not accurately describe the relationship between quantities in direct and inverse proportions.

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.

Correct Answer: A

Rationale: The key difference between a histogram and a bar graph is that a bar graph has gaps between the bars, while a histogram does not. This feature helps in visually distinguishing between the two. Choice B is incorrect because both types of graphs can show frequency. Choice C is incorrect as both graphs can be used for comparison. Choice D is incorrect as both types of graphs can have labels for better understanding.