A mixture of 30 percent benzene, 25 percent toluene, and 45 percent ethyl benzene is to be separated by distillation at atmospheric pressure, with 98 percent of the benzene and only 1 percent of the toluene in the distillate. 

(a) Calculate the minimum number of ideal plates and the approximate compositions of the products.

(b) Estimate the concentration of ethyl benzene in the distillate.

(c) If the distillation were carried out at 0.2 atm, would there be any change in N_min or in the heat duty?