What is the best estimate in meters for the average width of a doorway?

Correct Answer: B

Rationale: The correct answer is B: 1. The average width of a doorway typically ranges from 0.8 to 1.2 meters, making 1 meter a reasonable estimate. Choice A (0.5) is too narrow for a standard doorway. Choice C (10) is too wide for a typical doorway. Choice D (3) is also wider than the standard width of a doorway.

Correct Answer: A

Rationale: The correct answer is A: One. Any number raised to the power of zero is always equal to 1. This is a fundamental property of exponentiation. Choice B, 'Itself,' is vague and does not specify a numerical value. Choice C, 'Zero,' is incorrect as any nonzero number raised to the power of zero is 1, not 0. Choice D, 'Two,' is incorrect as any number raised to the power of zero is 1, not 2.

Correct Answer: A

Rationale: After one friend eats half of the pizza, the remaining half is divided equally among the three other friends. Each of the three friends receives 1/3 of the remaining half, not 1/6. Therefore, the correct answer is 1/3 of 1/2, which is 1/6 of the total pizza. The incorrect choices are: B. 1/3 - This is the correct portion of the remaining pizza each friend receives, not 1/3. C. 1/4 - This is not the accurate portion each friend receives after the first friend eats half of the pizza. D. 1/6 - This is the portion of the total pizza each friend receives, not the portion each friend receives after the initial half is consumed.

Correct Answer: B

Rationale: To solve the equation, distribute 3 to both terms inside the parentheses: 6x + 15 = 11x + 5. Then, move 11x to the left side by subtracting it from both sides: 6x - 11x = 5 - 15. Simplify to get -5x = -10. Divide by -5 to isolate x: x = 2. Therefore, the correct answer is x = 2. Choices A, C, and D are incorrect because they do not match the correct solution obtained by solving the equation step by step.

Correct Answer: A

Rationale: The phrase 'thrice a number' translates to 3x, and 'twelve less than' means subtracting 12 from it. Therefore, the correct expression is 3x-12. Choice B, '12-3x', represents '12 less than a number thrice,' which is the opposite of the given phrase. Choice C, '3-12x', does not correctly interpret the phrase provided. Choice D, '12x-3', represents 'a number thrice less than twelve,' which is not the same as the original phrase.

Correct Answer: C

Rationale: The correct answer is C: Bimodal. A bimodal distribution has two distinct peaks or modes. In this data set, the numbers 2 and 8 appear more frequently than other numbers, creating two modes (2 and 8). Choices A, B, and D are incorrect. Option A, 'Uniform,' describes a distribution where all values have equal frequency, which is not the case in this data set. Options B and D, 'Right-skewed' and 'Left-skewed,' refer to distributions where the data is skewed towards one side, which is not observed in this dataset. Therefore, the data set is best described as bimodal.

Correct Answer: D

Rationale: To convert yards to feet, you need to know that 1 yard is equal to 3 feet. Therefore, to find out how many feet are in 9 yards, you multiply 9 by 3, which equals 27 feet. Choice A (45 ft) is incorrect as it miscalculates by multiplying 9 by 5 instead of 3. Choice B (18 ft) incorrectly multiplies 9 by 2. Choice C (36 ft) is incorrect as it doubles the answer of 18 feet, which is also an incorrect calculation.

Correct Answer: A

Rationale: The correct answer is A: 1000 mL. This is a standard conversion in the metric system where 1 liter is equivalent to 1000 milliliters. Choice B, 100 mL, is incorrect as it represents only a tenth of a liter. Choice C, 10 mL, is incorrect as it represents only a hundredth of a liter. Choice D, 1 mL, is significantly less than a liter, as it is only a thousandth of a liter.

Correct Answer: A

Rationale: To find the perimeter of a rectangle, you add up all its sides. In this case, the length is 3 units greater than the width, so the length can be expressed as W + 3. The formula for the perimeter of a rectangle is 2W + 2(L), where L represents the length. Substituting W + 3 for L, the correct expression for the perimeter becomes 2W + 2(W + 3), which simplifies to 2W + 2W + 6 or 4W + 6. Choices B, C, and D do not correctly represent the formula for the perimeter of a rectangle. Choice B simply adds the width twice to 3, neglecting the length. Choice C multiplies the width by the sum of the width and 3, which is incorrect. Choice D combines the width and 3 times the width, which is not the correct formula for the perimeter of a rectangle.