The first question you need to investigate: Is there ANYnumber that is a common factor of 21, 30, and 44 ?If we can't find at least two of them, then we don't have to worry about "greatest".The factors of 21 are: 1, 3, 7, and 21.The factors of 30 are: 1, 2, 3, 5, 6, 10, 15, and 30.The factors of 44 are: 1, 2, 4, 11, 22, and 44.The only factor common to 21, 30, and 44 is '1'.Technically, I guess the answer to the question is 'Yes'. There is one common factor, so it'salso the greatest.
The factors of 21 are: 1, 3, 7, 21 The factors of 30 are: 1, 2, 3, 5, 6, 10, 15, 30 The factors of 44 are: 1, 2, 4, 11, 22, 44
The Greatest Common Factor of 21, 30, 44: 1
Just 1.
The Greatest Common Factor of 44, 42, 3: 1
Common factors of 26 and 44 are: 1 and 2.
The common factors of 44 and 70 are: 1 and 2
The Common Factors of 42 and 44 are 1, 2
The common factors of 44 and 121 are: 1 and 11
The common factors of 18 and 44 are 1 and 2.
21 = 3 x 7 30 = 2 x 3 x 5 44 = 2 x 2 x 11 GCF = 1
The common factors of 44 and 132 are 1, 2, 4, 11, 22 and 44.