In Building Problem 450, Design Data says the RoofLL (Snow) = 30psf, then in the solution, load combination should be either 1.2D+1.0E+0.5L (when take it as live load) or 1.2D+1.0E+0.2S (when take it as Snow load). Why in the NCEES's solution load combination uses 1.2D+1.0E+1.0L? I can't...