What is the range of potential exchange rates between US and UK?

Lets assume there are only 2 countries that produce 2 good. More specifically, suppose that the United States (US) and the United Kingdom (UK) each have 2 units of productive resources, 1 used to produce Wine, the other Cloth. The US can produce 40 units of Wine with 1 unit of productive resources and 40 units of Cloth with 1 unit of productive resources. The UK can produce 20 units of Wine with 1 unit of productive resources and 10 units of cloth with 1 unit of productive resources.

1. Given specialization, what is production before trade? After trade?

2. What are the gains from trade?

3. What is the rangeof potential exchange rates between US and UK?