What is the GCF of 6 and 12 and 20?

Answer 1

The factors of 8 are:

1, 2, 4, 8

The factors of 12 are:

1, 2, 3, 4, 6, 12

The factors of 20 are:

1, 2, 4, 5, 10, 20

The Greatest Common Factor:

GCF = 4

Answer 2

GCF of 12 and 24 and 20 = 4

prime factorization of:

12 = 2 x 2 x 3

24 = 2 x 2 x 3 x 2

20 = 2 x 2 --------x 5

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GCF=2 x 2

GCF = 4

Answer 3

What is the greatest common factor of 8, 20, and 30?

First check to see if the lowest number goes into the other two. 8 does not divide 20 or 30.

Next break the lowest number into it's factors. Don't include the number itself, because you already checked that in the previous step (i.e., 8 does not divide 20 or 30)

1x8 = 8

2x4 = 8

4x2 = 8 (the factors repeated, therefore we listed them all)

So check the highest factor:

4 divides 20 (20/4 = 5 which is an integer)
4 does not divide 30 (30/4 = 7.5 which is not an integer)

Check the next highest factor:
2 divides 20 (20/2 = 10 which is an integer)

2 divides 30 (30/2 = 15 which is an integer)

Therefore the greatest common factor of 8, 20 and 30 is 2.

Answer 4

The GCF is 2.

Answer 5

The GCF is 4.

Answer 6

The GCF is 1.

Answer 7

4

Answer 8

It is: 2