Final answer:
The BRFA experienced a revenue decrease of $250 due to the fare change which raised ticket prices, but decreased ridership. Alphonso's new budget constraint with higher bus fare prices decreases his purchasing power, effectively doubling the opportunity cost of each bus ticket in terms of the number of burgers he must give up.
Step-by-step explanation:
The revenue collected by the Big River Ferry Authority (BRFA) as a result of the fare change can be calculated by multiplying the price of the tickets by the number of tickets sold. Before the fare increase, the revenue was 0.25 dollars per ticket × 25,000 tickets, which equals $6,250. After the fare increase to 0.30 dollars, even though the number of tickets sold decreased to 20,000, the revenue became 0.30 dollars per ticket × 20,000 tickets, which equals $6,000. Therefore, the revenue decrease as a result of the fare change is $6,250 - $6,000 = $250.
In the budget constraint example, if the price of bus tickets in Alphonso's town increased from $0.50 to $1, while the price of burgers remained $2 and his weekly budget remained at $10, the new budget constraint would mean that Alphonso could afford fewer bus trips compared to before. For instance, previously he could take 20 bus trips (10 dollars ÷ 0.50 dollars per trip) or buy 5 burgers (10 dollars ÷ 2 dollars per burger), or some combination of the two that didn't exceed his budget. With the increased price of bus tickets, Alphonso can now only afford 10 bus trips (10 dollars ÷ 1 dollar per trip). The opportunity cost of each bus ticket has effectively doubled, as he now has to give up 2 burgers for each bus trip instead of 1 burger.