Commas are stripped from questions, so if you do not put spaces after commas, the result is a list of numbers becoming a single number.
Based on the digits, I guess there were three numbers 78, 91, 156 whose HCF is 13.
Two or more numbers are needed to find their HCF
To have a HCF, you need at least 2 numbers. There is no HCF in just 1 number.
the HCF is 6
The HCF is 5.
The HCF is 1
HCF = 14
The HCF of 16 & 33 is... 1
The HCF is 18
The HCF is 14.
The HCF is 1.
The HCF is 1.
The HCF is: 2