The vapor-liquid equilibrium curve of a binary mixture A-B,may be approximated by a linear equation over a narrow range of liquid mole fractions (0.2 < x${_A}$ < 0.3) as follows

y*${_A}$ = 1.325x${_A}$ + 0.121

Here y*${_A}$ is the mole fraction of A in the vapor. 100 moles of a feed (x${_A},{_F}$ = 0.28) is batch distilled to a final residue (x${_A},{_W}$ = 0.2). Using the Rayleigh equation, the number of moles of the residue left behind in the distillation unit, up to 2 digits after the decimal point, is $\_\_\_\_\_$