If there are two nonoverlapping nonintersecting circles in a plane four lines can be tangent to both circles at the same time How could the circles be arranged so that there are 3 or 2 or 1 or 0 li?

Hey, this one is nice! I will venture the following: * 3: make them tangent in one point, with no intersection * 2: make them have a small intersection, ie. crossing in two points * 1: make them tangent from the inside * 0: make one fall completely within the other Giving the explanation would just be killing the imagination.