What is a prime number?

Correct Answer: A

Rationale: The correct answer is A: 'A number divisible by only 1 and itself.' A prime number is a natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers. This definition aligns with choice A. Choice B is incorrect because not all prime numbers are divisible by 2 and 3. Choice C is incorrect as prime numbers are not divisible by any number other than 1 and themselves. Choice D is incorrect because a prime number has exactly two factors, 1 and itself, not three factors.

Correct Answer: A

Rationale: To convert Fahrenheit to Celsius, you start by subtracting 32 from the Fahrenheit temperature and then divide the result by 1.8. This formula accounts for the freezing point of water at 32°F and the conversion factor to Celsius. To convert Celsius to Fahrenheit, you multiply the Celsius temperature by 1.8 and then add 32. This process takes into consideration the conversion factor from Celsius to Fahrenheit and the freezing point of water. Choice B is incorrect as dividing by 2 instead of 1.8 would yield an inaccurate conversion. Choice C is incorrect as it involves incorrect operations for both conversions. Choice D is incorrect as subtracting 30 instead of 32 for Fahrenheit to Celsius and multiplying by 2 instead of 1.8 for Celsius to Fahrenheit would provide incorrect results.

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: A factor is a number that can be multiplied by another number to produce a third number. When you multiply factors together, you get the original number. For example, the factors of 12 are 1, 2, 3, 4, 6, and 12 because these numbers can be multiplied in pairs to give the product 12. Choice B is incorrect as it describes a divisor. Choice C is incorrect because factors are only multiplied, not divided. Choice D is incorrect because factors can be any number, not just those greater than 1.

Correct Answer: B

Rationale: The correct way to find the factors of a number is to identify all pairs of numbers that, when multiplied together, result in the given number. This method allows you to determine all the factors of the number. Choice A is incorrect because dividing the number by all possible numbers is not an efficient way to find its factors. Choice C is incorrect as listing all the multiples of the number does not give the factors. Choice D is unrelated to finding factors as adding the digits of a number together does not provide information about its factors.