How many balloons does it take for a person to fly roughly?

Question: How many balloons does it take for a person to fly roughly?
- Keywords:
  balloon,
  fly,
  force,
  mass,
  weight
Asked by carysuk to Asif, Laura, Lena, Sean, Viv on 14 Mar 2012.
- Laura Waters answered on 14 Mar 2012:
  
  Hmm, not sure. Depends on the weight of the person!
- Sean Murphy answered on 14 Mar 2012:
  
  You could fly with one really big balloon, or many small ones. Don’t try this at home!
  
  http://www.clusterballoon.org/learning/learning.htm

Question: How many balloons does it take for a person to fly roughly?