Exploring Factors and Prime Numbers

Which of the following numbers is a prime number?

• 21

• 29

• 35

• 49

What is the lowest common multiple (LCM) of 6 and 8?

• 24

• 36

• 48

• 18

Determine the highest common factor (HCF) of 45 and 60.

• 5

• 10

• 15

• 20

Find the prime factors of 84.

• 2² x 3 x 7

• 2² x 4 x 21

• 3 x 4 x 7²

• 2 x 3² x 5

List all the factors of 28.

• 1, 2, 4, 7, 14, 28

• 1, 2, 3, 7, 14, 28

• 1, 2, 4, 8, 14, 28

• 1, 2, 4, 7, 14, 21

Which of the following is a multiple of 9?

• 34

• 45

• 56

• 67

Identify the prime number from the list below.

• 51

• 53

• 57

• 63

Calculate the lowest common multiple (LCM) of 9 and 12.

• 18

• 24

• 36

• 48

What is the highest common factor (HCF) of 32 and 48?

• 8

• 12

• 16

• 24

Find the prime factors of 100.

• 2² x 5²

• 10²

• 5² x 10

• 2² x 3 x 5