Germanium to which $10^24$ m$^-3$ Ga atoms have been added is an extrinsic semiconductor at room temperature, and virtually all the Ga atoms may be thought of as being ionized $($i$.$e$.,$ one charge carrier exist for each Ga atom$).($a$)$ Is this material n$-$type or p$-$type? $($b$)$ Calculate the electrical conductivity of this material, assuming electron and hole mobilities of $0\mathrm{.}14$ and $0\mathrm{.}024$ m$^2/$V$-$s$,$ respectively. Units: $($ohm $-$ m$)^-1$