What is the conductivity of a semiconductor sample having electron concentration of $5 \times 10^{18} m^{−3}$, hole concentration of $5 \times 10^{19} m^{-3}$, electron mobility of $2.0\; m^2V^{-1} s^{-1}$ and hole mobility of $0.01 m^2V^{-1}s^{-1}$?
(Take charge of electron as $1.6 \times 10^{-19}C$)