Physics a bugee jumper please help?

A daredevil wishes to bungee-jump from a hot-air balloon 65.5 m above a carnival midway (figure below). He will use a piece of uniform elastic cord tied to a harness around his body to stop his fall at a point 10.0 m above the ground. Model his body as a particle and the cord as having negligible m and a tension force described by Hooke's force law. In a preliminary test, hanging at rest from a 5.00 m length of the cord, the jumper finds that his body weight stretches it by 1.60 m. He will drop from rest at the point where the top end of a longer section of the cord is attached to the stationary balloon.