Problem No$.6($Problem $3\mathrm{.}2,$ p$65)$: A $780-$N person sits $3m$ away from the fulcrum on a seesaw. A second person weighing $825N$ sits on the opposite side of the seesaw at a distance of $2\mathrm{.}8m$ away from the fulcrum.

$($a$)$ Draw the free body diagram and write equation of equilibrium in $Y$ direction. Then, calculate reaction force. $(1$ point$)$

$($b$)$ Determine the moment $($magnitude and direction in $+$ or $-$ sign$)$ created by the $780-N$ person with respect to fulcrum. Please note counterclockwise is $+$ and vice versa. $(1$ point$)$