Vietnam and Ecuador both produce shrimp and rice. Vietnam can produce 180 thousand pounds of shrimp or 60 thousand pounds of rice in a year. Ecuador can produce 130 thousand pounds of shrimp or 26 thousand pounds of rice in a year.

a. Vietnam's opportunity cost of producing one pound of rice is equal to
b. Ecuador's opportunity cost of producing one pound of rice is equal to

(a) 3 pounds of shrimp

(b) 5 pounds of shrimp

Explanation:

Opportunity costs refers to the costs or benefits that are foregone to select some other alternative.

Vietnam can produce 180,000 pounds of shrimp or 60,000 pounds of rice in a year:

Opportunity cost of producing one pound of rice = 180,000 ÷ 60,000

                                                                                  = 3 pounds of shrimp

Ecuador can produce 130,000 pounds of shrimp or 26,000 pounds of rice in a year:

Opportunity cost of producing one pound of rice = 130,000 ÷ 26,000

                                                                                  = 5 pounds of shrimp

Therefore,

According to the principle of comparative advantage, the Vietnam has a comparative advantage in producing rice because it has a opportunity cost of producing rice than Ecuador.

by knowing conditionality

explanation:

the first successful, urban blues recording, selling more than 75,000 copies, was made in year 1920.

mamie smith recorded the first commercially successful example of the urban blues,   with the recording of “crazy blues”."crazy blues" was recorded on august 10, 1920, in new york city. within a month of the release of “crazy blues” it had sold 75,000 copies.