10. The present value of cashflows is equal to V = 100. This value can move up the next period with u = 1.1 to V = 110. The up factor is used and the down factor is d = 1/u. Calculate the volatility o for one period, expressed in decimals rounded to two digits. Please use a period to indicate the decimal place (e.g. 0.75 instead of 0,75)