![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
Method 1:
\List the factors of each number.
\Factors of 66: 2, 3, 6, 11, 22, 33.
\Factors of 90: 2, 3, 5 , 6, 9, 10, 15, 18, 30, 45, 90.
\Factors of 150: 2, 3, 5, 6, 10, 15, 25, 30, 50,75, 150.
\Identify the greatest common factor.
\The greatest common factor of 66, 90 and 150 is 6.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step2.JPG\")
Method 2:
\Write the prime factorization of each number.
\66 = 2 × 3 × 11.
\90 = 2 × 3 × 3 × 5.
\150 = 2 × 3 × 5 × 5.
\The GCF is the product of the common prime factors in each number.
\GCF = 2 × 3 = 6.
\The greatest common factor of 66, 90 and 150 is 6.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The greatest common factor of 66, 90 and 150 is 6.