$$ \text { Find the sum of the vectors } \overrightarrow{\mathrm{a}}=(\hat{\mathrm{i}}-3 \hat{\mathrm{k}}), \overrightarrow{\mathrm{b}}=(2 \hat{\mathrm{j}}-\hat{\mathrm{k}})_{\text {and }} \overrightarrow{\mathrm{c}}=(2 \hat{\mathrm{i}}-3 \hat{\mathrm{j}}+2 \hat{\mathrm{k}}) $$