Я не экономист, но когда-то у меня был курс фундаментальной экономики. Давно это было, поэтому за правильность ответов не ручаюсь.
1.
(i) The opportunity cost of seeing the movie of Lord of the Rings is that of the cost of any other movie screened throughout the year that you could have watched instead of Lord of the Rings movie.
(ii) The opportunity cost of any other movie that you could have gone to watch instead of Lord of the Rings movie is the cost of Lord of the Rings movie.
The opportunity cost of seeing Lord of the Rings movie is less. In monetary terms it’s less by $4 - the cost of a Schweppes soft drink.
Note: Whether or not you would have purchased or got a free Shweppes soft drink that is the matter of your taste preference.
2
(a) The concept of opportunity cost is to be considered in this question. What would you be doing if you were not exercising? That’s the opportunity cost.
(b) What would you be doing instead of spending those extra hours studying each week? That’s the opportunity cost again.
(c) Marginal Benefits are the additional benefits received when one more pizza is consumed. And the marginal cost is the change in total cost in obtaining an extra pizza.
The cost of obtaining at least one pizza is $5, so the marginal cost of one pizza is $5. In obtaining 2nd, 3rd and all other pizzas you can eat the marginal cost of an extra pizza is zero. The shape of the curve is a straight line with positive slope between 0 and 1 pizza, and a horizontal line from 1 pizza onwards.
Marginal benefits in eating pizzas …well, the benefits will depend on your appetite and your taste preference in eating pizzas. You may eat one pizza and obtain all the benefits or it might be 3 pizzas that you will need to eat to satisfy your appetite. However, with each additional pizza you consume the marginal benefit obtained will be less. You would get to the point when you can’t eat pizzas at all. The benefit curve slopes downwards. Similarly to that of a typical "total" demand curve.
For your interest.
Economic efficiency occurs where the marginal cost curve and the marginal benefit curve intersect.
