Question 14
Let $OA$ and $OB$ be two radii of a circle with centre $O$, such that $OA\perp OB$, as shown in the diagram below. Let $P$ be a point on the circumference and $Q$ be the point on $AP$ such that $AP=4AQ$. If $OA=8$ cm, then what is the minimum possible length, in cm, of $BQ$?
