Please help

Consider two countries, China and Canada. Suppose that a worker in China can make 2 smartphones or 10 cellphone cases per week, and a worker in Canada can make 3 smartphones or 20 cellphone cases per week. a. In what sense do smartphones and cellphone cases cost less in Canada than in China? b. In what sense do smartphones cost less in China than in Canada? c. If China and Canada were to engage in trade, which country would export which good? d. How would the answer to the question in part c change if a worker in Canada could make 4 smartphones per week