please show the step by step and what formula used, thanks.

ww. 16) You would like to hold a protective put position on the stock of Avalon Corporation to lock in a guaranteed minimum value of $50 at year-end. Avalon currently sells for $50. Over the next year, the stock price will increase by 10% or decrease by 10 %. The T-bill rate is 5%. Unfortunately, no put options are traded on Avalon Co. 16) What would have been the cost of a protective put portfolio