Chapter 11, Problem 19P

In unit-vector notation, what is the net torque about the origin on a flea located at coordinates (0, −4.0 m, 5.0 m) when forces ${\stackrel{\to }{F}}_1$ = (3.0 N) $\hat{k}$ and ${\stackrel{\to }{F}}_2$ = (−2.0 N) $\hat{j}$ act on the flea?