$[15$ points$]$ Each pressure vessel in a proposed design for the desalinization of seawater is rated

$35\%$ recovery at flow rates between $850$ to $1,300\frac{m^3}{d}.$ Design an array system $($e$.$g$.,$ the

number of pressure vessels$)$ that will yield $2,000\frac{m^3}{d}$ of pure water $($e$.$g$.,$ permeate$)$ for a town

of $5,000$ people at a permeate recovery of $50\%.$