What is the greatest common factor of 40 100 and 140?

Answer 1

The greatest common factor of two or more numbers can be found by expressing each number as the product of prime numbers and then finding out what is common in the factorization of the numbers.

Prime factorization of 40 = 2 x 2 x 2 x 5

Prime factorization of 100 = 2 x 2 x 5 x 5

Prime factorization of 140 = 2 x 2 x 5 x 7

It can be seen that 2, 5, 2 x 2(or 4), 2 x 5(or 10) and 2 x 2 x 5(or 20) are common but 2 x 2 x 5(or 20) is the greatest, so 20 is the GCF.

Answer 2

The GCF is 20.