What is the least common denominator of two fractions?
- A. The smallest number that is a multiple of both denominators
- B. The smallest number that both fractions can divide into evenly
- C. The least common multiple of both denominators
- D. The greatest common factor of both denominators
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.
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In Mrs. McConnell's classroom, there are 14 students with brown eyes and 2 students with green eyes. What is the ratio of students with brown eyes to students with green eyes?
- A. 7:1
- B. 7:2
- C. 14:2
- D. 14:1
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.
Margery plans a vacation with costs for airfare, hotel (5 nights), sightseeing, and meals. If she receives a 10% discount on additional hotel nights, what will she spend?
- A. 1328.35
- B. 1373.5
- C. 1381.4
- D. 1417.6
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.
What is the formula for the area of a circle?
- A. A = πr²
- B. A = 2πr
- C. A = πd
- D. A = 2πd
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.
How many quarts are in a gallon?
- A. 1 quart
- B. 2 quarts
- C. 3 quarts
- D. 4 quarts
Correct Answer: D
Rationale: The correct answer is D, which is 4 quarts in a gallon. In the US customary system, there are 4 quarts in a gallon. Choice A is incorrect as it represents the equivalent of a quart, not a gallon. Choice B and C are incorrect as they are smaller quantities than a gallon and do not match the conversion of quarts to a gallon.
How many ounces are in a pound?
- A. 8 ounces
- B. 16 ounces
- C. 32 ounces
- D. 12 ounces
Correct Answer: B
Rationale: The correct answer is B: 16 ounces. There are 16 ounces in a pound. This conversion is a common measure of weight in the imperial system. Choices A, C, and D are incorrect because they do not reflect the correct conversion of ounces in a pound.