This problem will require some effort; it would help to consult section 5.2 - Stage by stage calculationsfor MC distillation.
A mixture of benzene (B), toluene (T), and cumene (C) is distilled with a partial reboiler and a totalcondenser. Assume that CMO applies. The bottom product compositions are xB = 0.1, xT = 0.3 and xc =0.6. The boilup ratio V(V with bar)/B = 1.0. The relative volatilities are αBT = 2.5, αTT = 1.0 and αCT = 0.21. What is the composition of the vapor leaving equilibrium stage above the partial reboiler?