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.

Again, as in such questions, there are normally two very strong possible answers. In this case, it is A or B. Somehow, I don’t find the OA answer very convincing.

I am inclined towards B.

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

If servers wrote regularly Thank you notes and customers won't revert to earlier tipping habits then it would increase servers average income.

I like your explanations on B as that was how I thought it should be. And the OA is B too.

But, is there anything wrong with A? Can't A function as an assumption too?

You see, if the impact was the same for both kinds of patrons, wouldn't A become an assumption that supports the argument?

I heard of the technique "If Yes/No" analysis. Shall we use it to go through choices A and B? From what ppl say, if an answer choice could support/weaken an argument whenever it switches from "If Yes" to "If No" or vice versa, then that is probably a correct answer. Choices that could not support or weaken whenever you use "If Yes" or "If No" would not be a correct answer. [Please, someone correct me if im wrong here]

For A

If Yes, A supports/strengthens the argument.

If No (ie. impact is different for both sets of patrons; some might tip a bit more and some a bit less, but ultimately all of them on average would tip more than previously), A cannot weaken the statement either. In fact, if you look closely, B actually still supports the statement.

Since both "If Yes/No" can only support the statement (Even when you swith to "If No", you still cannot weaken it), then this is probably not the answer.

For B
If Yes, B supports the statement. The reasonings are as provided by the previous posts

If No, B weakens the argument instantly. Say, if the patrons would revert back to tipping less, then the argument weakens.

Since both "If Yes/No" can support and weaken the argument, then this is probably the correct answer.

Hmm.... please let me know if you agree with my line of reasoning as it can be a bit hard to put it in words.

Thanks.

I am not sure of this technique. But let's discuss option 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

To me it's a weaker choice than B. Who will contribute more to server's increased revenue? Occasional or Regular Patrons. It's regular patrons who will contribute more. So if I see an option, which focuses more on sustaining regular customer's behavior I would pick that one.

seems to be B for me.

B.

Premise:
On randomly selected bills, 'thank you' note >> tip more (regardless of regulars or occasionals)

Conclusion:
Regular 'thank you' note >> continue to tip more (but on what assumption? Option B provides the assumption)

Extracted: "Tips on these bills were an average of three percentage points higher than tips on bills without the message. "

VS

(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.

>>In agreement.

clear B

Clearly B. If seeing 'Thank You' would become routine, then the tipping will also be back to routine. So B has to be true for the conclusion to be true.

+1 B OA?