A distillation column with a total condenser and a partial reboiler is separating an ethanol-water mixture. The feed is 30 mol% ethanol, feed rate is 1000 kmol/h, feed temperature is 40C. A distillate composition of 80 mol% ethanol and a bottoms composition of 5 mol% ethanol are desired. The external reflux ratio is R=4Rmin. The reflux is returned as a saturated liquid and CMO can be assumed. Find the optimum feed plate location and the total number of equilibrium stages required. Pressure is 1 atm