What is the greatest common factor of 10 25 and 40?

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.