)1 / 90, (), (). Find the rules and fill in the numbers!

)1 / 90, (), (). Find the rules and fill in the numbers!

9 out of 10, 3 out of 10, 1 out of 10, (1 / 30), 1 out of 90, (1 / 270), (1 / 810)
3/10=9/10*1/3
1/10=3/10*1/3
The latter is one third of the former