考虑下面的时间表，它显示了莎拉从参加 CHVRCHES 乐队的音乐会中获得的边际收益：音乐会 边际效益1 1502 1253 1004 755 606 50假设如果莎拉对参加和不参加某场音乐会不感兴趣，她将参加音乐会来打破平局。如果每场音乐会的价格为 81 美元，莎拉最大化她的盈余（或净收益），她将参加多少场音乐会？

1. Break Down the Problem

To determine how many concerts Sarah will attend to maximize her surplus, we need to compare her marginal benefit from attending each concert to the price of attending (which is $81). We will analyze each concert's marginal benefit.

2. Relevant Concepts

The main concept here is the comparison of marginal benefit (MB) and marginal cost (MC):

• If MB > MC, then Sarah will attend the concert.
• If MB < MC, then Sarah will not attend the concert.
• If MB = MC, she is indifferent.

3. Analysis and Detail

We have the following marginal benefits for each concert:

• Concert 1: MB = 150
• Concert 2: MB = 125
• Concert 3: MB = 100
• Concert 4: MB = 75
• Concert 5: MB = 60
• Concert 6: MB = 50

Now, we compare each MB to the cost of $81:

1. Concert 1: MB = 150 > 81 (Attend)
2. Concert 2: MB = 125 > 81 (Attend)
3. Concert 3: MB = 100 > 81 (Attend)
4. Concert 4: MB = 75 < 81 (Do not attend)
5. Concert 5: MB = 60 < 81 (Do not attend)
6. Concert 6: MB = 50 < 81 (Do not attend)

4. Verify and Summarize

Based on the comparison, Sarah will attend the first three concerts where the marginal benefits exceed the price she has to pay.

Final Answer

Sarah will attend 3 concerts to maximize her surplus.