A pro golfer has the amazing ability to consistently putt distances of 3, 5, 7, and 11 feet. Strangely enough, though, those are the only distances he can putt.
Currently, our golfer stands on the green with his ball 20 feet from the hole. What's the fewest number of strokes he can use to get the ball into the hole?
Assume that if the ball is hit farther than the distance remaining to the hole, it will roll over to the other side without going into the cup.