Select the lightest W section to carry

uniform distributed dead load of $1\mathrm{.}2$ k$/$ft

$($include self weight$)$ and $2\mathrm{.}4$ k$/$ft$,$ live load

from Table $3-2$ below. The simply

supported span is $20$ ft$.$ Use LRFD method

and select for the following steel: A$572$

Grade $50.$