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: A

Rationale: The sum of two odd numbers is even because odd numbers have a difference of 1 and adding them results in a multiple of 2. The sum of two even numbers is even because even numbers are multiples of 2. When an odd number and an even number are added, the result is odd because the even number contributes an extra 1 to the sum, making it an odd number. Therefore, the correct answer is A. Choices B, C, and D have incorrect combinations of the sum of odd and even numbers.

Correct Answer: C

Rationale: To compare the fractions, it is beneficial to convert them to decimals or find a common denominator. When converted to decimals: 1/2 = 0.50, 5/8 = 0.625, 2/3 ≈ 0.666, and 7/9 ≈ 0.778. Therefore, the correct order from least to greatest is 1/2, 5/8, 2/3, 7/9. Choice A is incorrect because it places 7/9 first, which is the greatest fraction. Choice B is incorrect as it incorrectly lists the fractions. Choice D is incorrect as it starts with 7/9, which is the largest fraction instead of the smallest.

Correct Answer: A

Rationale: To calculate Margery's total cost, we first need to find the cost without the discount. Let's say the original cost is x. With a 10% discount, she saves 10% of the cost of additional hotel nights. Since she is staying for 5 nights, the discount applies to 4 additional nights (5 - 1 night already included). Therefore, she saves 10% of 4 nights' cost. If x is the cost of 1 night, the total cost without discount is 5x. With the 10% discount, she saves 0.1 * 4x = 0.4x. So, the cost after discount is 5x - 0.4x = 4.6x. Given that the total cost is 5x for 5 nights, we can equate 5x to 4.6x to find x. Solving for x, we get x = Total cost / 5 = 5x / 5 = 4.6x / 5. Therefore, x = 4.6x / 5, which simplifies to x = 0.92 * 5x. This means 1 night's cost is 0.92 times the total cost for 5 nights. Given the total cost is $1328.35, we find the cost for 1 night is $1328.35 / 5 = $265.67. So, Margery will spend $1328.35 for her vacation.

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.