Answer
$n\lt -\frac{8}{3}$
Work Step by Step
$\frac{1}{3}\lt n+3$
$\mathrm{Switch\:sides}:$
$n+3>\frac{1}{3}$
$\mathrm{Subtract\:}3\mathrm{\:from\:both\:sides}:$
$n+3-3>\frac{1}{3}-3$
$\mathrm{Simplify}$
$n\gt\frac{1}{3}-3$
$n\gt\frac{1}{3}-3(\frac{3}{3})$
$n\gt\frac{1}{3}-\frac{9}{3}$
$n>-\frac{8}{3}$
$\mathrm{check}:$
$n=-1$
$-\frac{8}{3}\lt-1$
$\mathrm{true}$