I need help on some science things? 10 pts. for best answer!?

Well, there's this science olympiad contest thing. One of the events is called," BOTTLE ROCKET". The rocket with the longest amount of time in the air will be the winner. Parachutes are allowed this year. So, I need simple but detailed instructions to make a parachute that I can attach to a one-liter plastic soda bottle (which is my bottle rocket). There's also another event, called," FLING THAT PING PONG". I need simple but detailed instructions to build a catapult or a catapult-like machine that can fling a ping pong ball towards a target 3 meters away. The energy that I use must be supplied by a set of rubber bands. 10 points for best answer and thank you!