$10-10.$ A $36-ft$ simple span beam that supports a scrvice uniform dead load of $1\mathrm{.}0\frac{k}{f}t$ and a service concentrated live load of $25$ kips at midspan is laterally unbraced except at its ends and at the concentrated load at the midspan. If the maximum permissible centerline deflection under service live load equal $\frac{L}{360}$ total load and $\frac{L}{1000}$ live load, select the most cconomical W scetion of $50$ksi stecl, considering moment, shear, and deflection. The beam self$-$weight is included in the uniform dead load. Use $C_b=1\mathrm{.}0.$