Current Attempt in Progress

A charge $+1\mathrm{.}2C$ is placed at the center of the hollow spherical conductor with the inner radius $3\mathrm{.}5cm$ and outer radius $5\mathrm{.}9cm.$ Suppose the conductor initially has a net charge of $+2\mathrm{.}4C$ instead of being neutral. What is the total charge $($a$)$ on the interior and $($b$)$ on the exterior surface?

$($a$)$ Number Units

$($b$)$ Number Units