Country North has the comparative advantage in the production of tractor
Step-by-step explanation:
The principle of comparative advantage states that a country should specialize in the production of goods in which it have comparative cost advantage over other nations. i.e A country should focus on the production of the goods in which it has a lower opportunity cost in producing than someone else.
The question given shows that Country North has a lower opportunity cost (which is 21 watches) if it produces 3 tractors compared to country south which has an opportunity cost of 100 watches when it produces 5 tractors.
Hence, we can say that country North has a comparative advantage in the production of Tractors over country south because its opportunity cost when its produces tractors is lower than that of the country south
Statement 3 is QR=RT. This can be validified by the reason of Transitive Property of Equality. This property is applied when the situation is if a=c and b=c, then a=b. The same is true for QR=59 and RT=59, then QR=RT.