$10\mathrm{.}6-2.$ Analytical Method for Number of Trays in Absorption. Use the analytical equations in Section $10\mathrm{.}6$ for countercurrent tray contact to calculate the number of theoretical trays needed for Example $10\mathrm{.}6-3$ using $1\mathrm{.}3L_{\text{m}\text{i}\text{n}}^{\text{'}}.$