1. The problem statement, all variables and given/known data Suppose the selling price p of a product is linearly related to the quantity demanded q. If p=$15 when q=25, and p=$10 when q=100, and if q is at least 20 but not more than 150, find p as a function of q. 2. Relevant equations 3. The attempt at a solution I couldn't find a sample problem for this so I would just guess that the domain would be 20<q<150.