Answer:
1) country A has a comparative advantage in production of capital goods.
2) for country A 24 units of food can be traded for 10 units of capital goods,
for country B 30 units of food can be traded for 10 units of capital goods.
Explanation:
country A has a comparative advantage in production of capital goods because they have been able to produce more capital goods with the same amount of input (worker) than country B.
For country A, 120 units of food = 50 units of capital goods, therefore
10 units of capital good will be traded for (120 x 10)/50 = 24 units of food.
for country B 90 units of food is equivalent to 30 units of capital goods, therefore,
(90 x 10)/30 = 30 units of food