Find a GCF

Which pair of numbers has a GCF of 1?

• 51 and 17

• 20 and 9 

• 24 and 27

• 14 and 44

GCF of 27 and 70

• 3

• 5

• 7

• 10

GCF of 28 and 40

• 2

• 4

• 7

• 8

GCF of 24 and 56

• 2

• 4

• 6

• 8

GCF of 20 and 35

• 4

• 5

• 7

• 20

Find the greatest common factor of 20 and 30

• 2

• 5

• 10

• 15

GCF of 4 and 6

• 2

• 3

• 4

• 6

GCF of 50 and 100

• 10

• 25

• 50

• 5

What is the greatest common factor of 8 and 10?

• 1

• 3

• 4

• 2

Find the GCF of the pair of numbers: 21 and 30

• 6

• 1

• 7

• 3