PROBLEM $($ please solve all parts and show all steps$)$

$30\mathrm{.}1$ Spherical pellets of $1\mathrm{.}0cm$ diameter are spray$-$painted with a very thin coat of paint. The paint contains a volatile solvent. The vapor pressure of the solvent at $298$K is $1\mathrm{.}17$ x $10^4$ Pa$,$ and the diffusivity of the solvent vapor in air at $298$K is $0\mathrm{.}0962$ cm$^2/$s$.$ The amount of solvent in the wet paint on the pellet is $0\mathrm{.}12$ g solvent per cm$^2$ of pellet is $0\mathrm{.}12$g solvent per cm$^2$ of pellet surface area. The molecular weight of the solvent is $78$ g$/$gmole$.$