Chapter 2 Factors and Multiples

The diagram shows some factors of 56.

8 56 7 4

Identify three more factors of 56.

• 1, 2, 14

• 2, 3, 6

• 2, 3, 14

• 1, 14, 24

The sum of all the prime factors of 100 is

• 7

• 10

• 12

• 14

What is the highest common factor (HCF) of 16, 24

and 40?

• 2

• 4

• 6

• 8

Find the lowest common multiple of 15 and 40.

• 5

• 65

• 80

• 120

12 is the highest common factor of the following pairs

of numbers except

• 12, 24

• 24, 48

• 24, 36

• 36, 48

Find the lowest common multiple of 12, 15 and 20.

• 40

• 50

• 60

• 80

The lowest common multiple of 6, 8 and x is 24. Find

a possible value of x.

• 10

• 12

• 16

• 48

1, 3, 5, p, 15, 21, q, 105

Find the values of p and q.

• p = 8

  q = 34

• p = 7

  q = 35

• p = 6

  q = 34

• p = 5

  q = 33

Which numbers are factors of 12.

• 1, 2, 3, 4, 12

• 1, 2, 4, 6, 12

• 1, 2, 4, 6, 12

• 1, 2, 3, 4, 6, 12

State the common factors of 8 and 20.

• 1 , 2

• 2, 4

• 2, 4, 6

• 1, 2, 4