Answer
$M_O=36.7N*m \circlearrowleft$
Work Step by Step
We will sum the torques about point O
$(+ \circlearrowleft) \sum \tau_O$
$-(\cos(30^{\circ}))F*(\sin(45^{\circ}.3m)+(\sin(30^{\circ})F*(0.4m+\cos(45^{\circ}).3m)$
$-(\cos(30^{\circ}))(300N)*(\sin(45^{\circ}.3m)+(\sin(30^{\circ})(300N)*(0.4m+\sin(45^{\circ}).3m)$
$+36.7N*m$
$36.7N*m \circlearrowleft$
