Answer: 1, 2, 3, 6, 1
Explanation:
When listing all the factors for 18, 30 ,54....
18 , 30 , 54 to find the common factors. The common factors for 18,30,54 18 , 30 , 54 are 1,2,3,6 1 , 2 , 3 , 6 . The GCF (HCF) of the numerical factors 1,2,3,6 1 , 2 , 3 , 6 is 6 .
( Hope this helps )