The greatest common factor (GCF) of 21, 24, and 27 is 3.
To find the GCF, we first need to determine the factors of each number:
- Factors of 21: 1, 3, 7, 21
- Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24
- Factors of 27: 1, 3, 9, 27
Next, we identify the common factors among these numbers. The factors that appear in all three lists are:
- Common factors: 1, 3
Among these common factors, the greatest one is 3. Thus, the greatest common factor of 21, 24, and 27 is 3.