How about 17 out of 20 minus 8 out of 9 plus 3 out of 20? Simple calculation?

How about 17 out of 20 minus 8 out of 9 plus 3 out of 20? Simple calculation?

=(17 / 20 + 3 / 20) - 8 / 9
=8 / 1-9
=One in nine