Can you lose 10 pounds in 3 weeks?

The other day I had a good friend ask me this question: "Can you lose 10 pounds in 3 weeks?" She wanted to know if it is possible to lose 10 lbs in such a short amount of time. I told her it depends: does she want to lose 10 pounds of fat or just 10 pounds in general? It would be extremely difficult to lose that much body fat in only 3 weeks. Not impossible... just very challenging. On the other