For which value of $u$ will $2^{u}>100 u$?
$\mathrm{Az} y=2^{u}$ exponential function and the $y=100 u$ line, when plotted, show that the two curves intersect at a point where $0100 u$. This value of $u$ can be found immediately by trial and error. For $u=10$, $2^{u}=1024,100 u=1000$, thus $2^{u}>100 u$, if $u \geq 10$.