(Thanks Pariah, Scras, and val for participating! )
Citizens of Canada pay as much income tax (percentage-wise) as they make dollars per week. What is the optimal salary in Canada?
This can be determined by plotting the function and finding its maximum. (We could also do calculus if we didn't want to deal with it visually, but graphing was easier.)
Our function is: income = salary - (salary * percentage), where percentage = salary/100
The following is a graph of that function: http://www.wolframalpha.com/input/?i=plot&a=
As you can see, the plot is maximized at 50. Ergo, our optimum salary is $50.