Find the price of a 1-year European call option for 1 pound with a strike price of 1.6 $/Pound if the current spot rate is 1.9 $/Pound and next year spot rate can either be 2.1 $/pound or 1.7 $/pound. The U.S. interest rate is 10% and the UK interest rate is 7%.

Answer: $0.321155

0.1/1.1 + (1.9/1.07 - 1.7/1.1)

I would like to know where the 0.1/1/1 came from if possible.

Thanks