You are considering buying a share of stock in a firm that has the following two possible payoffs with the corresponding probability of occurring. The stock has a purchase price of $15.00. You forecast that there is a 30% chance that the stock will sell for $30.00 at the end of one year. The alternative expectation is that there is a 70% chance that the stock will sell for $10.00 at the end of one year. What is the expected percentage return on this stock, and what is the return variance?