Puzzle for September 12, 2008

Friday is Jeans Day at our school. To wear jeans you have to contribute a dollar to whichever cause the school is collecting money for this month. Our school is raising money for a new library display this month for example. Turns out that half of our teachers and twenty times as many students contributed to the $210 we raised this week.

How many teachers and students participated. How many teachers work in our building?