Find an optimal combination of sales and days using the concept of optimization of marginal change:

 

Days      Ponce   Ventas  Bayamon             Ventas

0              0                              5,000    

1              15,000                   18,000  

2              23,000                   28,000  

3              30,000                   37,000                  

4              36,000                   40,000  

Goal: maximize profit on both sites

Limiting factor: 5 days

How much is sold in each town and the number of days?

(Just in case Ponce and Bayamon are towns)