Understanding Prime Numbers

Which of the following numbers is a prime number?

• 20

• 12

• 17

• 8

What is a characteristic of composite numbers?

• They are all prime numbers.

• They have only one factor.

• They have more than two factors.

• They have exactly two factors.

Why is the number one not considered a prime number?

• It is greater than two.

• It is a composite number.

• It has only one factor.

• It is an even number.

What is the first step in checking if a number is prime?

• Check if it is less than 10.

• Check if it ends in 5.

• Check divisibility by 2 and 3.

• Check if it is even.

Which of the following is true about prime numbers greater than five?

• They are all even numbers.

• They all end in 1, 3, 7, or 9.

• They are all multiples of 5.

• They all end in 0, 2, 4, or 6.