b) Consider a forward contract on a non-dividend-paying stock. Each contract convers one share and matures one year from now. Assume the risk-free rate is constant at 10% per annum and no arbitrage opportunity exist. The current stock price is $100 and Jack immediately shorts one forward contract. Six month later, the stock price is $60 and there is no change in interest rates, what is the value of Jack's contract at this time? Show your working and explain your answer. (10 marks)