2. suppose Dmitri is currently using combination D, producing one train per day. His opportunity cost of producing a second train per day is (1 drums, 2 drums, 13 drums, or 15 drums?) per day.
3. Now, suppose Dmitri is currently using combination C, producing two trains per day. His opportunity cost of producing a third train per day is (1 drum, 5 drums, 8 drums, or 13 drums?) per day.
4. From the previous analysis, you can determine that as Dmitri increases his production of trains, his opportunity cost of producing one more train (decreases, increases, or remains constant?)
5. Suppose Dmitri buys a new tool that enables him to produce twice as many trains per hour as before, but it doesnt affect his ability to produce drums. Use the green points (triangle symbol) to plot his new PPF on the previous graph.
6. Because he can now make more trains per hour, Dmitri's opportunity cost of producing drums is (higher than, lower than, the same as?) it was previously.