Use the Graph to Answer the Question

Use the graph to answer the question.
- Mike decides to buy shares of companies A, B, and C, which were initially selling for the
same price. The changes in each stock's value are shown in the graph above. Could Mike
ever have made a profit off stock A if he had sold at the right time? If so, when should he
have sold to make the maximum profit? Answer the same questions for stocks B and C.