1/3 + 0.3 = 1/3 + 3/10 = (10+3)/30 = 13/30

3/5 - 0.75 = 3/5 - 75/100 = 60/100 - 75/100 = -15/100 = -3/20

-1/6 - 0.5 = -1/6 - 3/6 = -4/6 = -2/3

3/30 - 0.95 = 1/10 - 95/100 = 10/100 - 95/100 = -85/100 = -17/20