231 Force P producing a clockwise moment about the origin

Ratio and proportion
$\dfrac{d}{6} = \dfrac{1}{\sqrt{5}}$

$d = \frac{6}{\sqrt{5}} \, \text{ ft}$
 

Moment at point O
$M_O = Pd$

$300 = P(\frac{6}{\sqrt{5}})$

$P = 50\sqrt{5} \, \text{ lb}$ down to the right from A to B       answer