What is the greatest common factor of 51 and 17, 26 and 65?

What is the greatest common factor of 51 and 17, 26 and 65?

The greatest common factor of 51 and 17 is 17
The greatest common factor of 26 and 65 is 13

80 and 16 10 and 9 15 and 14 17 and 51 25 and 100 39 and 10 greatest common factor and least common multiple

The greatest common factor of 80 and 16 is 16, and the least common multiple is 80
The greatest common factor 1 and the least common multiple 90 of 10 and 9
The greatest common factor 1 and the least common multiple 10 of 15 and 14
The greatest common factor 17 and the least common factor 51 of 17 and 51
The greatest common factor of 25 and 100 is 25 and the least common factor is 100
39 and 10 greatest common multiple 1 least common factor 390

The common factors of 12 and 18 are [【

The common factors of 12 and 18 are [1,2,3,6] and the greatest common factor is [6]

What is the greatest common factor of 12 and 18?

36