10.6 Exercise 21

What is the torque about the origin of the force $\left(5.0 \hat{i} - 2.0 \hat{j} + 1.0 \hat{k}\right) \text{N}$ if it is applied at the point whose position is: $\overset{\rightarrow}{r} = \left(−2.0 \hat{i} + 4.0 \hat{j}\right) \text{m}?$