Design beam in LFRD $(1\mathrm{.}2$D $+1\mathrm{.}6$LL$)$

Determine how much each beams weigh in ft$^3$ & compare which is more efficient.

$20$ft of tributary $--$ the dead load material can be assumed to be whatever

$(90\%$ limit of $36$ ksi$)$

Will thumbs up thank you!

Dimensions: $20\text{'}$ at top and $50\text{'}$ on the left