Difficult Physics Problem that NO ONE CAN SOLVE?

A skydiver with a parachute jumps from a high altitude. The skydiver and parachute weigh 192 lb. During the first 10 sec before the parachute opens, the air resistance amounts to kv, with k=3/4. Thereafter while the parachute is open the resistance amounts to kv with k=12. Find the velocity of the falling skydiver 15 sec after the jump.