Consider the attached table which gives information about the labor requirement coefficients for two goods Oranges and Grapes for two countries

Consider the attached table which gives information about the labor requirement coefficients for two goods Oranges and Grapes for two countries Mexico and Argentina along with their respective total available labor supply. Assume the labor is the only resource needed in the production of the goods and that labor is homogeneous within a nation. Draw the corresponding total production table and the appropriate PPF curve for Argentina by plotting Grapes vertically and Oranges horizontally. What is the pre-trade domestic opportunity cost ratio (MRT) for Argentina of producing one unit of orange in terms of the units of grapes to be given up?

Country Oranges (o) Grapes (G) Total Labor Supply

Mexico 0.50 0.25 200

Argentina 0.20 0.40 400

Answer: 1 O= .50 G

Can you please explain step by step on how the answer is .50 G