Example in Section 5.1

Consider the call option example given in Section 5.1, where the initial price of the security is assumed to be 100. But, now suppose that the price at time 1 can be any of the values 50, 200, and 100. Suppose that we want to price an option to purchase the stock at time I for the fixed price of 150. For simplicity, let the interest rate r equal to zero. Show that no arbitrage is possible for any option cost in the interval [o, 50/3].