Choosing Salaries

Your principal wants to hire you to work for her for ten days. She will pay you either $6.00 each day for all ten days; or $1.00 the first day, $2.00 the second day, $3.00 the third day, and so on; or $0.10 the first day and each day there after twice the amount of the day before. In which way would you earn the most money? In which way would you earn the least money?

Extension:
Using the guidelines above, how would you negotiate your salary if your principal wanted to hire you for n days?

(Source: Mathematics Teaching in the Middle School, May 1994)