A mixture that contains 40% by mole n-heptane in n-decane is to be separated in a series

Question:

A mixture that contains 40% by mole n-heptane in n-decane is to be separated in a series of flush separators until a stream is obtained that contains at least 95% n-heptane. Determine the number of separators needed, their temperature, and the recovery of n-heptane if all separators are at 1.013 bar and V/L = 3 in all separators. Txy data are given below:

X1 T (C) X1 Y T (C) 0.00 0 173.63 0.55 0.9206 116.53 0.05 0.25146 164.52 0.60 0.93525 113.84 0.10 0.42826