prep 08 119

crystal_10

In a study conducted in Pennsylvania, servers in various restaurants wrote “Thank you” on randomly selected bills before presenting the bills to their customers.  Tips on these bills were an average of three percentage points higher than tips on bills without the message.  Therefore, if servers in Pennsylvania regularly wrote “Thank you” on restaurant bills, their average income from tips would be significantly higher than it otherwise would have been.

Which of the following is an assumption on which the argument relies?

(A) The “Thank you” messages would have the same impact on regular patrons of a restaurant as they would on occasional patrons of the same restaurant.

(B) Regularly seeing “Thank you” written on their bills would not lead restaurant patrons to revert to their earlier tipping habits.

(C) The written “Thank you” reminds restaurant patrons that tips constitute a significant part of the income of many food servers.

(D) The rate at which people tip food servers in Pennsylvania does not vary with how expensive a restaurant is.

(E) Virtually all patrons of the Pennsylvania restaurants in the study who were given a bill with “Thank you” written on it left a larger tip than they otherwise would have.

看解析说这道题目是一道削弱题目，因此选B，这道题目为啥是削弱题，不太明白。正确答案是B

joii

assumption题 把选项negate之后就是个削弱题

飞天小猪Piggy

spicytaco 发表于 2018-10-14 15:56
结论说: regularly wrote “Thank you” on restaurant bills, their average income from tips would be  ...

同意

清酉湘竹2018

逻辑链：
前提：写了thank you的bill, 客人支付的平均tips更多
结论：如果都写thank you, 那么服务人员可以获得更多的tips
问得出该结论基于什么假设

A.  thank you留言对于同一饭店的惯常客人与对于该饭店的偶尔光顾的客人有一样效果，不相关
B. 常规性看到thank you留言不会让客人revert之前给更多小费的习惯——即常规性看到thank you 留言客人会依然保持给更高小费。文中的结论基于这一假设。因为如果客人会revert，那如果所有bill都写上thank you, 久而久之客人就不会给更多小费了
C. 不相关
D. 不相关
E. 该测试中每一个看到"thank you"的客人都给了更多的小费——为study的测试结果即逻辑链中的“前提”给了更多细节，是和“前提”相关，和推理过程不相关。

spicytaco

结论说: regularly wrote “Thank you” on restaurant bills, their average income from tips would be significantly higher than it otherwise would have been.

B .Regularly seeing “Thank you” written on their bills would not lead restaurant patrons to revert to their earlier tipping habits.

Regularly seeing THank You would not revert to earlier tipping这样才能保证家经常性的使用thank you 会持续增加消费。如果没有这条，客户见惯了后就回归已经给小费的习惯，就不会有持续性的效果了。

没有b的话，b里提到的就成了逻辑漏洞，would revert to earlier tipping habit 那结论就不成立了
解析所谓的削弱就是同样的意思 。。b取反就可以削弱结论。。所以不能让它存在 ，只有让b存在