$1.$ If the absorption factor of a particular system is $0\mathrm{.}8$ and the minimum solvent flow rate required for a certain operation is $100$ kg$/$h$,$ what would be the actual solvent flow rate to ensure a margin of safety of $20\%?$

$2.$ Considering a packed column for gas absorption$,$ if the height of a transfer unit $($HTU$)$ is $0\mathrm{.}5$ meters and the number of transfer units $($NTU$)$ required for a desired separation is $10,$ what is the total height of the packed section needed?