Initial volume of liquid was (36 2/3 gallons + (4 5/6 gallons)+(27 1/12 gallons) +(17 3/5 gallons), or approx.:
36.67
4.83
27.50
17.60
---------
86.60 gallons. This was c-20.75 gallons (20.75 gallons short of capacity).
To answer this question, solve this equation for c:
c = 20.75 gallons + 86.60 gallons = 107.35 gallons (tank capacity)