A woman at a point $A$ on the shore of a circular lake with radius $r = 3$ wants to arrive at the point $C$ diametrically opposite $A$ on the other side of the lake in the shortest possible time. She can walk at the rate of $4 \text{mph}$ and row a boat at $2 \text{mph}.$

What is the shortest amount of time it would take her to reach point $C$? hours

What is the longest amount of time it would take her to reach point $C$ following a path like the path in the figure? hours