Optimization question?

A lifeguard spots a swimmer in distress 400m off shore. The lifeguard is 1100m down shore from a position that is perpendicular to the swimmer and the shore. If he can run at 5m/s and swim at 3m/s, where should he enter the water to reach the swimmer and the shore. If he can run at 5m/s and swim at 3m/s, where should he enter the water to reach the swimmer the quickest?