Linear momentum $\overrightarrow{p}=2\hat{\mathrm{i}}+4\hat{\mathrm{j}}+5\hat{\mathrm{k}}$ and position vector is $\overrightarrow{r}=3\hat{\mathrm{i}}-\hat{\mathrm{j}}+2\hat{\mathrm{k}},$ the angular momentum is given by

Two particles $A$ and $B$ are moving as shown in the figure. Their total angular momentum about the point $O$ is,