Consider a 1-time step model with two risky stocks and no bonds. Assume both stocks are initially 1, and the first stock can go up to 1.1 or down to 0.9, and the second stock can go up to 1.05 or down to .98). Is there arbitrage in this model? (hint use matrix inversion). Write down the state price vector and the risk-neutral probabilities. Harder: if the .98 is changed to .85, construct an arbitrage strategy for this model