题目:https://goo.gl/XZz4T3
Refer to Figure 3-8. If the production possibilities frontiers shown are
each for one day of production, then which of the following combinations of
coffee and soybeans could Chile and Colombia together make in a given day?
A. 4 pounds of coffee and 16 pounds of soybeans
B. 8 pounds of coffee and 15 pounds of soybeans
C. 16 pounds of coffee and 10 pounds of soybeans
D. 24 pounds of coffee and 4 pounds of soybeans
我的想法:
当初是想说，将两个直线方程式合并后，得到新的方程式
再将选项的数字代入验证是不是正确的答案，但一直找不
到方法做，问友人也只知道答案用凑的出来是A，好苦恼
求版上的大大为我解答QQ