On Friday, 1/9 of band practice was spent trying on uniforms. The band spent 1/6 of practice on marching. The remaining practice time was spent playing music. What fraction of practice time was spent playing music?
1/9 = 6/54
1/6 = 9/54
6/54 + 9/54 = 15/54
54/54 - 15/54 = 39/54
39/54 = 13/18
13/18 of practice time was spent playing music.