The position vectors of P and Q are respectively $\bar {a}$ and $\bar {b}$. If R is a point on $\overleftrightarrow{PQ}$ such that $\overrightarrow{PR}= 5 \overrightarrow{PQ},$ then the position vector of R is :

Question

\[\begin {array} {1 1} (1)\;5 \bar {b} - 4 \bar {a} & \quad (2)\;5 \bar {b} + 4 \bar {a} \\ (3)\;4 \bar {b} - 5 \bar {a} & \quad (4)\;4 \bar {b} +5 \bar {a} \end {array}\]