Answer:
HCF = 6
Step-by-step explanation:
Listing the factors of each number
18 is 1, 2, 3, 6, 9, 18
30 is 1, 2, 3, 5, 6, 10, 15, 30
36 is 1, 2, 3, 4, 6, 9, 12, 18, 36
common factors are 1, 2, 3, 6
the HCF is 6
1 out of 12
12-11=1
7.127
Hope this helps!