You need at least two numbers to find a GCF.
There cannot be a greatest common factor (GCF) of just one number. To be common there need to be at least two numbers. If you find all the factors of two or more numbers, and you find some factors are the same ("common"), then the largest of those common factors is the Greatest Common Factor.
The largest number that divides both 27 and 40 is called the greatest common divisor (GCD). The GCD of 27 and 40 is 1, since they have no common factors other than 1. Thus, the largest number that goes into both 27 and 40 is 1.
What are the common factors of 15, 25 and 40
The factors of 40 are 1,2,4,5,8,10,20 and 40. For them to be common, they need to be compared to another set of factors.
The greatest common factor (GCF) of 10, 25, and 40 is 5. To find the GCF, you need to determine the factors of each number and then identify the largest factor that is common to all three numbers. The factors of 10 are 1, 2, 5, and 10. The factors of 25 are 1, 5, 25. The factors of 40 are 1, 2, 4, 5, 8, 10, 20, and 40. The largest factor that is common to all three numbers is 5, making it the greatest common factor.
The common factors of 30 and 40 are 1, 2, 5, 10
Common factors are those that can be divided into two different numbers. For 4 and 40, their common factors are: 1, 2, 4, -1, -2, -4. Of these, the largest number is 4 (and this is therefore the greatest common factor).
The common factors of 36 and 40 are 1,2 and 4.
The common factors of 40 and 135 are 1 and 5.
The common factors of 40 and 2015 are 1 and 5.
The common factors of 18 and 40 are: 1, 2.
Common factors of 38 and 40 are 1 and 2.