Question: what is the greatest common factor of 4 and 40?
Answer: Greatest Common Factor (GCF) of two numbers the factors of 40 are 1, 2, 4, 5, 8, 10, 20 and 40, and the factors of 50 are 1, 2, 5, 10, 25 and 50. Here is a procedure to find the greatest common factor of two or more numbers.