Find degrees of freedom (DOF)?

Essential oils compound is to be extracted from biomass by means of TCB solvent leaching in a single-stage extractor. The extractor is to treat 1000kg of biomass. The untreated biomass contains 350kg of essential oil and is contaminated with 30kg of TCB. The solvent feed contains 15kg of oil and 675kg of TCB. The experimental data indicating how the solution retained depends on the concentration of the solution is given in Table 1 below. Assume the equilibrium for this system is of YA=XA type