Correct Answer: A

Rationale: The correct answer is A: 7:1. To find the ratio, divide the number of students with brown eyes (14) by the number of students with green eyes (2), which equals 7. Therefore, the ratio of students with brown eyes to students with green eyes is 7:1. Choice B (7:2) is incorrect as it does not accurately represent the ratio of students with brown eyes to green eyes. Choice C (14:2) is incorrect because the ratio should be simplified, and 14:2 simplifies to 7:1. Choice D (14:1) is incorrect as it does not consider the number of students with green eyes.

Correct Answer: A

Rationale: The correct formula for the area of a circle is A = πr², where π is a mathematical constant approximately equal to 3.14159 and r is the radius of the circle. Choice B, A = 2πr, represents the circumference of a circle, not the area. Choice C, A = πd, incorrectly uses the diameter (d) instead of the radius in the formula for area. Choice D, A = 2πd, is also related to the circumference of the circle, not the area. Therefore, option A is the only correct formula for calculating the area of a circle.

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: To solve the equation x + 5 = x - 3, we aim to isolate x. By subtracting x from both sides, we get 5 = -3, which is not possible. This indicates that the equation has no solution. Therefore, the correct answer is x = -5. Choices B, C, and D are incorrect as they do not yield a valid solution when substituted back into the original equation.

Correct Answer: B

Rationale: To calculate the percentage of rainfall that occurs during October, divide October's rainfall (4.5 inches) by the total rainfall (29.38 inches) and multiply by 100. So, (4.5 / 29.38) * 100 = 15.31%. Among the choices given, option B, 0.151, is the closest to this calculated percentage. Options A, C, and D are not correct as they do not match the accurate calculation based on the provided data.