$9-1$ to $9-10.$ Using both LRFD and ASD, select the most economical sections, with $F,=50$ksi, tinless otherwise specified, and assoming fult lateral bracing for the compression fanges. Working or service loads are given for each case, and beam self$-$wrights are not included.

$9-2$

$=12k$

$=20k$

$=$ beam self$-$weight

$9-8.$ The accompanying figure shows the arrangement of beams and girders that are used to support a $5-$in reinforced concrete floor for a small industrial building. Design the beams and girders assuming that they are simply supported. Assume full lateral support of the compression flange and a live load of $80$ psf$.$ Concrete weight is $150l\frac{b}{f}{t}^3.$

oor continues I all sides