9/5
180 over 100 is the same as 18 over 10 which is the same as 9 over 5 which is the same as 1 and 4 over 5 (1 and a four fifths) which is the same as 1.8
16/180 = 4/45
180/210 = 6/7
15/180 = 1/12
9/180 = 1/20
It is 2 over 3.
2/5 keep dividing it until its to its simplest form :)
8/45
11/90
18/55
1/18