You have saved $$2,500$ from your summer job and would like to invest it$.$ Using your knowledge of the stock market and knowing the power of early investments, you have identified three stocks to purchase. Cost per share and expected return per share for the next year are given in this table:

Stock

A

B

C

Price$/$share

$$12$

$$15$

$$30$

Return$/$share

$$8$

$$7$

$$11$

Identify the decision variables and constraints for a linear programming model, helping you with a decision to maximize your return on investment.

How many decision variables do you find?