What is the greatest common factor of 8 20 40?

Answer 1

The greatest common factor of 8 and 40 is 8.

The common factors of 8 and 40 are 1, 2, 4, and 8.

Definition: A factor is a divisor - a number that will evenly divide into another number. The common factors of two or more numbers are all the factors that the numbers have in common. The greatest common factor of two or more numbers is the largest factor that the numbers have in common.

Methods:

You might notice that 8 is a factor of 40. Since 8 is also the largest possible factor of itself, that means 8 is the greatest common factor.

Another way to determine the greatest common factor is to find all the factors of the numbers and compare them.

The factors of 8 are 1, 2, 4, and 8.

The factors of 40 are 1, 2, 4, 5, 8, 10, 20, and 40.

The common factors are 1, 2, 4, and 8. Therefore, 8 is the greatest common factor.

The greatest common factor can also be calculated by identifying the common prime factors and multiplying them together.

The prime factors of 8 are 2, 2, and 2.

The prime factors of 40 are 2, 2, 2, and 5.

The prime factors in common are 2, 2, and 2, so the greatest common factor is 2 x 2 x 2 = 8.
The greatest common factor of the numbers 8 and 40 is 8.
The GCF is 8.

Answer 2

Yes, there is no number greater than 8 that can be multiplied by something to equal 8, therefore it is the highest possible GCF between 8 and 40. Since 8 is also a factor of 40, it must be the answer.

Answer 3

40

1x40

2x20

4x10

5x8

1, 2, 4, 5, 8, 10, 20, 40

80

1x80

2x40

4x20

5x16

8x10

1, 2, 4, 5, 8, 10, 16, 20, 40, 80

Greatest Common Factor (GCF)

The GCF of 40 and 80 would be 40 because that is the largest number that appears on BOTH lists.

Answer 4

The greatest common factor of the numbers 8, 20, and 40 is 4.

Answer 5

SInce 8 is a factor of 40, it is automatically the GCF.

Answer 6

The GCF is 4.