You have driven 800 miles on a vacation and then you notice that you are only 15 miles from an attraction you hadn’t known about, but would really like to see. In computing the opportunity cost of visiting this attraction you had not planned to visit, you should include

c. the cost of driving the next 15 miles, but not the cost of driving the first 800.

Explanation:

When calculating your OPPORTUNITY COST i.e your cost of not simply continuing on your journey in this instance, the relevant calculation is to calculate the cost of the next 15 miles to that previously unknown attraction.

This is because the 800 miles had already been accounted for in your journey to your initial destination and need not be double counted.

However, as you are now deviating from the plan for a 15 miles trip, that should be included in your existing opportunity cost calculation which already includes the original 800 miles.

answer: marginal utility of the fourth brownie is 0.

explanation: marginal utility is the addtional utility gained from the consumption of one more unit of a good. it is given by,

so, marginal utility at the 4th unit will be given by

since, the values are not given here, you can simply find marginal utility at fourth unit by subtracting total utility at 3rd unit from total utility at 4th unit.