OG 13 CR 95

Here is the question from Official Guide to the GMAT 13th edition page 529 question 95:

Studies in restaurants show that the tips left by customers who pay their bill in cash tend to be larger when the bill is presented on a tray that bears a credit-card logo. Consumer psychologists hypothesize that simply seeing a credit-card logo makes many credit-card holders willing to spend more because it reminds them that their spending power exceeds the cash they have immediately available.

Which of the following, if true, most strongly supports the psychologists' interpretation of the studies?

A. The effect noted in the studies is not limited to patrons who have credit cards.
B. Patrons who are under financial pressure from their credit-card obligations tend to tip less when presented with a restaurant bill on a tray with credit-card logo than when the tray has no logo.
C. In virtually all of the cases in the studies, the patrons who paid bills in cash did not possess credit cards.
D. In general, restaurant patrons who pay their bills in cash leave larger tips than do those who pay by credit card.
E. The percentage of restaurant bills paid with a given brand of credit card increases when that credit card's logo is displayed on the tray with which the bill is presented.

Answer should be B.

We want to establish that the psychologist's hypothesis holds true.

The psychologist says that seeing the credit card logo reminds customers that they have more purchasing power. Therefore, we can infer that credit card logo on the tray influences buyer behavior.

If we can find an option that concurs with our inference then that option should be the right answer.

B does just that. When people have credit card obligations, seeing the logo reminds them of such obligations and they are influenced to leave little tip. Therefore, in this case, credit card logo influences buyer behaviour. This matches with the psychologist's hypothesis. Therefore, B.

OA is B.

Great explanation from Bharat!

I went over to GMATClub and found an explanation from one of our very best Veritas experts, Karishma. She has taken the time to write a very thorough explanation which I share with you below. If you are over on GMATClub look for Veritas Prep Karishma!


"Let's look at the argument:

Argument: Studies show that cash tips left by customers are larger when the bill is presented on a tray that bears a credit-card logo.

Why would that be? Why would there be a difference when the tray has no logo and when the tray has a credit card logo?

Psychologists' hypothesize that seeing a credit-card logo reminds people of the spending power given by the card they have (and that their spending power exceeds the cash they have right now).

We have to support the psychologists' interpretation.

Say, I change the argument a little and add a line:

Argument: Studies show that cash tips left by customers are larger when the bill is presented on a tray that bears a credit-card logo. Patrons under financial pressure from credit-card obligations tend to tip less when presented with a restaurant bill on a tray with credit-card logo than when the tray has no logo.

Now, does the psychologists' interpretation make even more sense. Understand that the psychologists' interpretation is only that 'seeing a logo reminds people of their own credit card status'. The part 'that their spending power exceeds the cash they have right now' explains the higher tips. If we are given that some tip more on seeing that card logo and some tip less on seeing it, it makes sense, right? Different people have different credit card obligation status. Hence, people are reminded of their own card obligation status and they tip accordingly. Hence, option (B) makes the probability of psychologists' interpretation being true stronger because it tells you that in case of very high card obligations, customers tip less. This is what you would expect if the psychologists' interpretation were correct.

It's something like this:
Me: After 12 hrs of night time sleep, I can't study.
Your theory: Yeah, because your sleep pattern is linked to your level of concentration. After a long sleep, your mind is still muddled and lazy so you cant study.
Me: After 4 hrs of night time sleep, I can't study either.

Does your theory make more sense? Sure! You said 'sleep pattern is linked to your level of concentration'. If I sleep too much, my concentration gets affected. If I sleep too little, again my concentration gets affected. So your theory that 'sleep pattern is linked to your level of concentration' certainly makes more sense.


Option (E) (the one that confuses people) is incorrect.
(E) - 'The percentage of restaurant bills paid with given brand of credit card increases when that credit card's logo is displayed on the tray with which the bill is prepared.'

This options supports the hypothesis that card logo reminds people of their own card (not of their card obligations). The psychologists' interpretation talks about the logo reminding people of their card status (high spending power or high obligations)"