# Find a unit vector parallel to the vector....

If $$\overrightarrow {a} = \hat{i} + \hat{j} + \hat{k}$$ and
$$\overrightarrow {b} = 2\hat{i} − \hat{j} + 3\hat{k}$$  and
$$\overrightarrow {c} = \hat{i} − 2\hat{j} + \hat{k}$$
find a unit vector parallel to the vector $$2\overrightarrow {a} – \overrightarrow {b} + 3 \overrightarrow {c}$$