Question

what is the greatest common factor of 20 and 30

Answer 1

Factors of 20 = 1 , 2 , 4 , 5 , 10 , 20.

Factors of 30 = 1 , 2 , 3 , 5 , 10 , 15 , 30.

Common factors of 20 and 30 = 1, 2 , 5 , 10

So 

The greatest common factor 20 and 30 is 10.

Answer 2

Given:

The two numbers 20 and 30

To find:

The greatest common factor of 20 and 30

Solution:

We can find the greatest common factor of 20 and 30 by finding the factors of the numbers.

Factors of 20 are 1 , 2 , 4 , 5 , 10 , 20

Factors of 30 are 1 , 2 , 3 , 5 , 6 , 10 , 15 , 30

Here, The common factors of 20 and 30 are 1 , 2 , 5 , 10

The greatest number among 1 , 2 , 5 , 10 is 10

Therefore,

The greatest common  factor of 20 and 30 is 10

Final answer:

The greatest common  factor of the numbers 20 and 30 is 10