The volume of the parallelepiped whose edges are

The volume of the parallelepiped whose edges are $(-12 \hat{\mathrm{i}}+\lambda \hat{\mathrm{k}}),(3 \hat{\mathrm{j}}-\hat{\mathrm{k}})$ and 

$(2 \hat{\mathrm{i}}+\hat{\mathrm{j}}-15 \hat{\mathrm{k}})$ is 546 cubic units. Find the value of $\lambda$.