How many quarts are in 1 liter?

Correct Answer: B

Rationale: To convert liters to quarts, you can use the conversion factor 1 liter ≈ 1.06 quarts. Therefore, 1 liter is approximately 1.06 quarts. Choice A is incorrect because 1 quart is not equivalent to 1 liter. Choice C is incorrect as 2 quarts is more than 1 liter. Choice D is incorrect as 0.5 quarts is half of 1 liter.

Correct Answer: A

Rationale: In mathematics, "is" signifies equality, meaning that the values or expressions on both sides of the equation are the same. For example, in the equation 2+2=4, the phrase "2 + 2 is 4" indicates that the sum of 2 and 2 equals 4. "Multiply" refers to the operation of combining two numbers to obtain a product. For instance, in the expression 34, we multiply 3 by 4 to get 12. "Subtract" means to take one number away from another, resulting in a difference. For example, in 5−2, we subtract 2 from 5 to get 3. "Add" refers to the operation of combining two numbers to get a sum. For example, in 2+3, we add 2 and 3 to get 5.

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: The correct way to find the radius of a circle when given the diameter is by dividing the diameter by 2 to get the radius (Radius = Diameter · 2). When given the circumference, you need to divide the circumference by 2π to find the radius (Radius = Circumference · 2π). Choice A provides the accurate formulas for finding the radius in both scenarios. Choices B, C, and D present incorrect formulas that do not align with the correct calculations for determining the radius of a circle based on the given information.

Correct Answer: A

Rationale: The correct formula to find the circumference of a circle is C = 2πr, where C represents the circumference and r is the radius of the circle. Choice B, Circumference = πr², represents the formula for the area of a circle rather than the circumference. Choice C, Circumference = 2r², is incorrect as it does not involve π in the formula. Choice D, Circumference = r²π, has the terms reversed compared to the correct formula; the formula should start with the constant (2) multiplied by π, followed by the radius.