OPM 2015 Problem 4

Let $[ABCD]$ be a parallelogram and $P$ a point between $C$ and $D$ . The line parallel to $AD$ that passes through $P$ intersects the diagonal $AC$ in $Q$ . Knowing that the area of $[PBQ]$ is $2$ and the area of $[ABP]$ is $6$ , determine the area of $[PBC]$ .