Problem:
The current traded price of an underlier is $10, and it will be either $5 or $15 at the end of the period. Riskless borrowing and lending for the period is 10% p.a. A Europeand Vanilla Put option on the underliner with stike price of $9 is trading in the market.
Required:
Question: What is the no-arbitrage value of the European vanilla Put option?
Note: Provide support for rationale.