The position vector of the point which divides the join of points with position vectors \(\rm \vec{a}+\vec{b}\) and \(2 \rm \vec{a}−\vec{b}\) in the ratio 1 ∶ 2 is
1
\(\frac{3 \vec{a}+2 \vec{b}}{3}\)
2
\(\rm \vec{a}\)
3
\(\frac{5 \vec{a}−\vec{b}}{3}\)
4
\(\frac{4 \vec{a}+\vec{b}}{3}\)