The greatest common factor (GCF) of 30 and 40 is 10.
To find the GCF, we can start by identifying the factors of both numbers:
- Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30
- Factors of 40: 1, 2, 4, 5, 8, 10, 20, 40
Next, we look for the common factors between the two lists. The common factors of 30 and 40 are 1, 2, 5, and 10. Among these, the greatest is 10.
Therefore, the greatest common factor of 30 and 40 is 10.