The greatest common factor of the numbers 42, 90 and 81 is 3.
The GCF is 45.
The GCF is 5.
The GCF is 10.
3
3
The GCF of 42 49 and 81 is 1. There are no common factors aside from 1. If you meant 4249 and 81, then it is still 1.
The GCF is 3.
The GCF is 3.
The GCF is 1.
The GCF is 3.
The GCF is 3.
The GCF is 3.