Isn't there a minimum altitude of something like 2200 feet to deploy your parachute while skydiving? I'm assuming that's so the parachute has enough time to slow you down.
The air resistance of a parachute is huge. That's why the b value is so large. Think of it this way. Have you ever seen "in jump" video of two sky divers? When the first deploys the chute it looks like the sky diver is actually moving upward at a fantastic rate. What the chute is actually doing is slowing the sky diver very quickly. As the solution suggests.