3. On the sides $AB$ and $CD$ of the inscribed quadrilateral $ABCD$, which is not a trapezoid, points $P$ and $R$ are marked, respectively, such that $AP: PB = CR: RD$. On the segment $PR$, a point $Q$ is chosen such that $PQ: QR = AB: CD$. Find the ratio of the areas of triangles $AQD$ and $BQC$, given that $AD = x$ and $BC = y$.