please solve this question and draw a gragh for part b of the number of stages above and below optimal feed tray

12000 kg/hr is to be produced in a continuous fractionation column. The system has been designed at a recovery of 95 wt% benzene and 95 wt% toluene in the overhead and bottom products, respectively. The feed has a mixture of 60 wt% benzene and 40 wt% toluene. This feed is preheated so that it enters the column with a molar vaporization equal to 88 kmole/hr and a reflux ratio of 3.5 Rmin has been used. Data provided: VLE data for benzene to toluene system: 0 0.20 0.40 0.60 0.80 1.0 Y 0 0.38 0.61 0.78 0.92 1.0 Molecular weight of benzene = 78 and of toluene = 92, respectively Do the following: (a) Find number of plates and locate the optimal feed plate. (b) Find the number of stages if the feed stage position is above and below the optimal feed tray