Consider a portfolio consisting of 6 stocks and 10 put options on the stocks. The current stock price is S=100 and the strike price of the options is X=100. The stock price can take on only two values at maturity T given by Su=120 and Sd=90. The risk free rate is 5%.

Find the value of a put option P with strike price X=100.

Find the value of a call option C with X=100 by using the Put-call parity. Verify your answer by calculating the price C directly.