please solve it fast I need it within half hour

Question $2$:

For the cascade shOwn in the figure below assume constant molar overflow, and determine:

a$)$ The maximum vapor flow in the cascade.

b$)$ The flow rate and composition of the vapor entering the last stage from the bottom $(V_{N+1})$

c$)$ Determine the number of stages required to produce the vapor $(V_1)$ with the required composition.

$\backslash$table$[[x,0\mathrm{.}100,0\mathrm{.}200,0\mathrm{.}300,0\mathrm{.}400,0\mathrm{.}500,0\mathrm{.}600,0\mathrm{.}700,0\mathrm{.}800,0\mathrm{.}900],[y,0\mathrm{.}294,0\mathrm{.}484,0\mathrm{.}616,0\mathrm{.}714,0\mathrm{.}789,0\mathrm{.}849,0\mathrm{.}897,0\mathrm{.}938,0\mathrm{.}971]]$