180 - 1 7/30 = 178 23/30
11/30 - 1/5 - 1/6 = 0
19/20 minus 11/12 = 1/30
2/5 - 1/6 = 12/30 - 5/30 = 7/30
1/3 − 3/10 = 1/30
21/30 - 5/30 = 16/30 = 8/15
I believe it is 1/30
30 min/180 hours = 30 min/(180*60) min = 30/(180*60) = 1/36030 min/180 hours = 30 min/(180*60) min = 30/(180*60) = 1/36030 min/180 hours = 30 min/(180*60) min = 30/(180*60) = 1/36030 min/180 hours = 30 min/(180*60) min = 30/(180*60) = 1/360
9/10 − 1/3 = 17/30
8/15 − 1/6 = 33/90 or 11/30
30
30 - 1 = 29
180 - 25% = 180 x (1 - (25/100)) = 180 x 0.75 = 135