I need help with this

Eileen's elegant earrings produces pairs of earrings for its mail order catalogue business. each pair is shipped in a separate box. she rents a small room for $150 a week in the downtown business district that serves as her factory. she can hire workers for $275 a week. there are no implicit costs. what is the marginal product of the second worker?

Suppose that a worker in agland can produce either 10 units of organic grain or 2 units of incense per year, and a worker in zenland can produce either 5 units of organic grain or 15 units of incense per year. there are 20 workers in agland and 10 workers in zenland. currently the two countries do not trade. agland produces and consumes 100 units of grain and 20 units of incense per year. zenland produces and consumes 50 units of grain and no incense per year. if each country made the decision to specialize in producing the good in which it has a comparative advantage, then the combined yearly output of the two countries would increase by a. 30 units of grain and 100 units of incense. b. 30 units of grain and 150 units of incense. c. 50 units of grain and 90 units of incense. d. 50 units of grain and 130 units of ince

Anew 2-lane road is needed in a part of town that is growing. at some point the road will need 4 lanes to handle the anticipated traffic. if the city's optimistic estimate of growth is used, the expansion will be needed in 4 years and has a probability of happening of 40%. for the most likely and pessimistic estimates, the expansion will be needed in 8 and 15 years respectively. the probability of the pessimistic estimate happening is 20%. the expansion will cost $ 4.2 million and the interest rate is 8%. what is the expected pw the expansion will cost?