Three salesmen work for the same company, selling the same product. And, although they are all paid on a weekly
basis, each salesman earns his paycheck differently. Salesman A works strictly on commission. He earns $65 per sale,
with a maximum weekly commission of $1,300. Salesman B earns a weekly base salary of $300, plus a commission of
$40 per sale. There are no limits on the amount of commission he can earn, Salesman C does not earn any commission,
His weekly salary is $900.
The weekly paycheck amount for each salesman, p, is a function of the number of sales, s, they had in that week.