Problem $2$

Select the lightest $20ftW$ section available to

support a tensile load of $P_d=60k$ and $P_L=20k.$

Assume there are $2$ lines $($lines are $2"$ apart$)$ of $\frac{3}{4}"$

bolts in each flange $(4$ lines total$)$ and $4$ bolts per

line @ $3"$ o$.$c$.$ and $3"$ to end. Assume A$992$ steel.

Dimensions are from centers of bolt holes.