How many feet are equal to 1 yard?

Correct Answer: B

Rationale: The correct answer is B: 3 feet. This is because 1 yard is equivalent to 3 feet. The conversion factor between yards and feet is 1 yard = 3 feet. Choice A (4 feet) is incorrect as it represents the conversion of 1 yard to 4 feet, which is inaccurate. Choice C (2 feet) is incorrect as it underestimates the number of feet in 1 yard. Choice D (5 feet) is incorrect as it overestimates the number of feet in 1 yard.

Correct Answer: B

Rationale: The correct answer is B: 3 feet. This is because 1 yard is equivalent to 3 feet. The conversion factor between yards and feet is 1 yard = 3 feet. Choice A (4 feet) is incorrect as it represents the conversion of 1 yard to 4 feet, which is inaccurate. Choice C (2 feet) is incorrect as it underestimates the number of feet in 1 yard. Choice D (5 feet) is incorrect as it overestimates the number of feet in 1 yard.

Correct Answer: A

Rationale: The mnemonic 'King Hector Died By Drinking Chocolate Milk' aids in recalling metric prefixes in order: kilo-, hecto-, deca-, base (meter, liter, gram), deci-, centi-, milli-. Choice B does not provide a relevant mnemonic for metric conversions. Choices C and D do not offer a helpful phrase for remembering metric prefixes, making them incorrect.

Correct Answer: B

Rationale: The correct answer is B: 100 cm. 1 meter is equivalent to 100 centimeters. Choice A (10 cm) is incorrect as it represents the conversion of decimeters to centimeters. Choice C (1,000 cm) is incorrect as it represents the conversion of meters to millimeters. Choice D (10,000 cm) is incorrect as it represents the conversion of meters to centimeters with an extra zero.

Correct Answer: B

Rationale: To convert liters to milliliters, you need to multiply by 1000 since there are 1000 milliliters in 1 liter. Therefore, 0.5 liters x 1000 = 500 milliliters, making choice B the correct answer. Choices A, C, and D are incorrect because they do not correctly convert liters to milliliters.

Correct Answer: B

Rationale: The correct answer is B: 2.54 cm. One inch is equivalent to 2.54 centimeters in the metric system. This conversion factor is commonly used in converting measurements between the imperial and metric systems. Choice A (1.54 cm), Choice C (3.54 cm), and Choice D (4.54 cm) are incorrect conversions and do not represent the accurate metric equivalent of 1 inch.

Correct Answer: B

Rationale: To convert kilometers to meters, you need to multiply by 1,000 since there are 1,000 meters in a kilometer. Therefore, 345 km multiplied by 1,000 equals 345,000 meters. Choice A is incorrect as it incorrectly places the comma. Choice C is incorrect as it adds an extra zero at the end. Choice D is incorrect as it adds an extra zero at the beginning, resulting in an incorrect conversion.

Correct Answer: A

Rationale: The correct answer is A: 10^-9 meters. 1 nanometer (nm) is equivalent to 10^-9 meters. This conversion is commonly used in various scientific fields, including nanotechnology, to represent extremely small lengths. Choice B, 10^-6 meters, is incorrect as it represents a micrometer, not a nanometer. Choice C, 10^-12 meters, is incorrect as it would be a picometer, which is smaller than a nanometer. Choice D, 10^-15 meters, is incorrect as it would be a femtometer, much smaller than a nanometer.

Correct Answer: A

Rationale: To find the product of 0.5 and 20, you multiply them together. 0.5 x 20 = 10. This calculation involves multiplying a decimal (0.5) by a whole number (20). Choice A, '10', is the correct answer. Choice B, '15', is incorrect as it does not accurately represent the result of multiplying 0.5 by 20. Choices C and D, '20' and '25', are also incorrect as they do not reflect the correct calculation. This question assesses your ability to perform basic arithmetic operations involving decimals and whole numbers.