A ladder rests against a frictionless vertical wall, with its upper end $6m$ above the ground and the lower end $4m$ away from the wall. The weight of the ladder is $500 N$ and its centre of gravity at $\left(\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$3$}\right.\right)rd$ distance from the lower end. Wall’s reaction will be, in $N$ :-