In a study conducted in Canada,servers in various restaurant

[306097127]

In a study conducted in Canada,servers in various restaurants wrote"Thank you"on randomly selected bills before presenting the bills to their customers.Lips on these bills were an average of three percentage points higher than tips on bills without the message.Therefore,if servers in Canada regularly wrote"Thank you"on restaurant 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"Thanke 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 Canada does not vary with how expensive a restaurant is
E Virtually all patrons of the Canadian restaurants in the study who were given a bill with"Thank you"written on it left a larger tip than they otherwise would have

the correct answer is B,but B also have the possiblity for the increase came only from occasional patron,because it's start from"regularly"
Is there anyone could help me to explain?

[306097127]

up!!!

[jnelson0612]

up!!!

Hi there,
Just a reminder; when you reply to your own post you move it to a later position in the queue. :-)

Have you seen this thread? http://www.manhattangmat.com/blog/index ... -problems/ This thread walks through this problem in a step by step manner.

Please read through and then let us know if you have further questions.

[JbhB682]

Hi -

I thought A was wrong for the following reason :

If there is a difference b/w how regular customers tip vs. only occasional customers tip

Then the argument breaks

The argument is staying -- this strategy of saying "thank you" works in ALL cases (high end / low end restaurants || regular customers or occasional customers) -- In all such cases -- customers tip more if they see --" Thank you" notes

Choice A is saying -- well that is not true ...

[JbhB682]

Similarly on D -- i thought negating D destroyed the argument

The argument is staying --

“” if you write thank you notes -- servers go home with much higher income

Choice D when negated says

-- tips vary depending on how expensive a restaurant is

Doesn't this break the argument because -- if it is cheap restaurant , you are not going to be tipped very much

[Sage Pearce-Higgins]

I encourage you to be much more precise with your analysis of the argument. Find the conclusion, as it's actually written in the argument (not your own interpretation of it). Here it is: Therefore,if servers in Canada regularly wrote"Thank you"on restaurant their average income from tips would be significantly higher than it otherwise would have been.

If we make answer D negative, then it becomes: The rate at which people tip food servers in Canada does vary with how expensive a restaurant is.

If we're applying the negation of answer D to the argument, then we need to think "okay, we know that the rate at which people tip varies, but does that affect what would happen when waiting staff write "thank you" on the check?". Remember that the argument is only claiming that the tips would be 'significantly higher', not that the tips will big. This doesn't destroy the argument.

It seems that you're getting distracted by your own assumptions. Just because the rate at which people tip varies doesn't mean that we know that it's high in expensive restaurants or low in cheap restaurants. It might be the opposite! Or the rate might vary, but not by much. I would encourage you to try to see answer D as irrelevant before applying the negation test.

[JbhB682]

Hi Sage --

I had a chance to look at option D again and this is my analysis a second review

-- D is talking about a totally different group of people (D is talking about customers who tip vs. customers who don't tip at all.)

For example -- Option D is saying , in expensive restaurants and /or cheap restaurants, 80 % of customers tip

The argument is talking about a different scenario --- the argument is talking about HOW MUCH a customer tips once he /she decides to tip so its a different group all-together

Is that a fair reason to eliminate D ?

[Sage Pearce-Higgins]

I'm not so sure. The phrase 'the rate at which people tip' means, in my opinion, the percentage tip that the average customer gives in addition to the bill, e.g. the average customer tips at 20% of the bill. It seems that you're interpreting it as meaning the percentage of customers who give a tip. I think you're reading the phrase as 'the rate of people who tip' or similar.