Question 12
In the figure below, the chord $AF$ passes through the origin $O$ of the circle, and is perpendicular to the chord $BC$. It is given that $AB=17$ cm, $CD=5$ cm. Suppose $\frac{BE}{ED}=\frac mn$, where $m$ and $n$ are positive integers which are relatively prime. What is the value of $m+n$?
