Problem $1(10$ points$)$ Problem $4\mathrm{.}7$ from Text

A simply supported beam has a $20-$ft span and carries a uniform dead load $($DL$)$ of $800$ lb$/$ft $$ not

including the beam self$-$weight $$ and a concentrated live load $($LL$)$ at midspan of $9$ kips. Design the beam

if b $=12$ in$.$ fc$\text{'}=4$ ksi fy $=60$ ksi