What is the largest number that is factor of 20 and 30?
The largest number that is a factor of both 20 and 30 is the greatest common factor (GCF) of the two numbers. To find the GCF, we need to determine the factors of each number. The factors of 20 are 1, 2, 4, 5, 10, and 20, while the factors of 30 are 1, 2, 3, 5, 6, 10, 15, and 30. The largest number that is common to both lists is 10, making it the largest factor of 20 and 30.