In which case can the government improve outcomes?

Question 5-8 related to the oil market. Let PO be the price of oil and QO be the quantity transacted of oil. Determine which happened to PO  and QO in the following situations.   The US government begins subsidizing electric vehicles which do not require gas.

Question 17-21 refer to the following graph   From the indifference curve, we see the consumer is indifferent between (18 pizzas, 2 sodas) and   

Question 17-21 refer to the following graph   Suppose the price of pizza decreases to $1. The quantity demanded of pizza increases by how many units?  

Suppose the indifference curve was computed from a survey. All of the following are reasons the indifference curves may be unreliable except

For questions 10-13, the following graph describes the market for train tickets.   What is consumer surplus when there is a $8 tax?

Question 17-21 refer to the following graph   Now suppose the income increases to $48, the price of pizza is $2, and the price of soda is $2. The increase in pizza consumption (when compared to question 19) is  

For questions 10-13, the following graph describes the market for train tickets.   Suppose that there is a $6 positive externality for the market. What should the government do to ensure the quantity transacted is optimal?

Question 14-16 considers the market for milk. Suppose there is a 25% increase in income, what happens to the quantity demanded of milk?

Suppose the government imposes a price floor at B. Consumer surplus with the price floor equals the area defined by which points?