A distillation column with a partial reboiler and a total condenser is being used to separate a mixture of benzene, toluene, and cumene. The feed is $40\mathrm{.}0$ mol$\%$ benzene, $30\mathrm{.}0$ mol$\%$ toluene, and $30\mathrm{.}0$ mol$\%$ cumene. The feed is input as a saturated vapor at $1\mathrm{.}0$ atm pressure, and the column is at the same pressure. We desire $99\mathrm{.}0\%$ recovery of the toluene in the bottoms and $98\mathrm{.}0\%$ recovery of the benzene in the distillate. The reflux is returned as a saturated liquid, and GMO ean be assumed. Equilibrium can be represented as constant relative volatilities. Choosing toluene $($T$)$ as the reference component, ast $=2\mathrm{.}25$ and ac $-0\mathrm{.}210.$