Suppose That the Productivity Per Worker in the Corn and Barley

Suppose that the productivity per worker in the corn and barley industries of China and Russia are as follows: $\begin{array} { l c c c } &&\underline{{ \text { Number of Bushels per day } }} \\ &\underline{ \text { Corn } } &&\underline{ \text { Barley } } \\\text { China } & 1 & \text { or } & 2\\\text {Russia}&1& \text { or } &3\end{array}$ a) What is the opportunity cost of 1 bushel of corn for China? For Russia?
b) What is the opportunity cost of 1 bushel of barley for China? For Russia?
c) Suppose there are 1000 workers in both China and Russia. Draw a production possibility curve for China and Russia