Factors, multiples and prime

Which is a common factor of 12 and 20?

• 6

• 10

• 4

• 5

Which of these numbers is prime?

• 12

• 7

• 15

• 21

What are the factors of a prime number?

• 1 and itself

• 2 and 5

• 5 and 10

• 1,2 and 4

What is the only even prime number?

• 6

• 20

• 100

• 2

What is the lowest common multiple of 3 and 5?

• 30

• 15

• 5

• 3

What are the factors of 6?

• 6

• 6, 12 and 18

• 1,2,3 and 6

• 0

What is 5²?

• 10

• 25

• 100

• 15

What is 2³?

• 3

• 8

• 18

• 6

What are common factors of 20 and 100?

• 5

• 1

• 2

• 40

Which prime numbers can you add together to make 20?

• 17 and 3

• 18 and 2

• 20 and 0

• 7 and 13