EXAMPLE $4-3.$ McCabe$-$Thiele method

A distillation column with a total condenser and a partial reboiler is separating an ethanol$-$water mixture. Feed is $20\mathrm{.}0$mol$\%$ ethanol, feed rate is $1000\mathrm{.}0$ kmo$\frac{l}{h},$ and feed temperature is $80F.$ Distillate is $80\mathrm{.}0$mol$\%$ ethanol, and bottoms is $2\mathrm{.}0$mol$\%$ ethanol. External reflux ratio is $\frac{5}{3}.$ Reflux is a saturated liquid, and CMO can be assumed. Pressure is $1\mathrm{.}0$atm. Find optimum feed plate location as stages above the reboiler and total number of equilibrium slages.