8,9

Draw a circle with the given radius, tangent to the given line and the given circle. How many solutions does this problem have?
Let $r$ be the given radius, $R$ and $O$ be the radius and center of the given circle. The center of the desired circle lies on the circle $S$ with radius $|R \pm r|$ and center $O$. On the other hand, its center lies on the line $l$, parallel to the given line and at a distance $r$ from it; there are two such lines. Any point of intersection of the circle $S$ and the line $l$ can serve as the center of the desired circle. The problem can have from 0 to 8 solutions.