The highest common factor of 6 & 7 is 1
6 (leaving 6 and 7 respectively)
3.
They are all divisible by 1 which is their HCF
The HCF is 7.
The GCF is 7.
The GCF is 7.
The GCF is 7.
The GCF is 1.
The GCF is 7.
The GCF is 6.
the HCF is 6
6 is the HCF of 18 & 48