Question
Let a variable line passing through the centre of the circle $x^2+y^2-16 x-4 y=0$, meet the positive co-ordinate axes at the points $A$ and $B$. Then the minimum value of $O A+O B$, where $O$ is the origin, is equal to
Let a variable line passing through the centre of the circle $x^2+y^2-16 x-4 y=0$, meet the positive co-ordinate axes at the points $A$ and $B$. Then the minimum value of $O A+O B$, where $O$ is the origin, is equal to