On Wednesdays, Kate usually buys some guava juice. But the only place she can buy guava juice is the local health foo...

Claire on May 27, 2019

Question

Why is the answer A instead of D? Thanks!

5 Replies

Ravi on May 27, 2019

@claire_crites,

Happy to help. Let's take a look at (A) and (D).

In looking at the argument in the stimulus, we know that it's valid.

Kate usually buys guava juice on Wednesday. If she buys guava juice,
she must get it at the local health food store. Therefore, she
sometimes shops at the health food store on Wednesdays.

Since Kate usually buys guava juice on Wednesdays, we know that she
usually goes to the store on Wednesdays. In the answer choices, we
need to find a valid argument that mirrors this argument's structure.

(D) says, "Most teachers at the Culinary Institute are allowed to use
the institute's main kitchen. Dinners at Cafe Delice are only prepared
in that kitchen. So dinners at Cafe Delice must sometimes be prepared
by Culinary Institute teachers."

The problem with (D) is that it's invalid. Based on the premises, it's
totally possible that dinners at Cafe Delice are never prepared by
Culinary Institute teachers, so this is why (D) is out.

(A) says, "Only teachers at the Culinary Institute are allowed to use
the institute's main kitchen. Most dinners at Cafe Delice are prepared
in that kitchen. So at least some dinners at Cafe Delice must be
prepared by Culinary Institute teachers."

With (A), we know that if teachers are allowed to use the main
kitchen, then the individual has to be a teacher at the institute. We
know that dinners at the cafe are often prepared in this kitchen. From
this, we know that some of the dinners at the cafe have to be made by
institute teachers. This is a valid argument that mirrors the
structure of the one in the stimulus, so it's the correct answer
choice.

Does this make sense? Let us know if you have any more questions!

on June 18, 2020

the quantifier language in the stimulus is different than the one in A, so I don't get how based off of that this answer can be picked when it doesn't mirror the stimulus' argument structure?

on October 18, 2020

^^^

Aneesh on November 16 at 03:39AM

If you reorder the sentences in A like I've shown below, it might correspond better with the answer you were expecting to see. I had this question as well^. Could someone please confirm?

"Most dinners at Cafe Delice are prepared in that kitchen. Only teachers at the Culinary Institute are allowed to use the institute's main kitchen. So at least some dinners at Cafe Delice must be prepared by Culinary Institute teachers."

Jay Wednesday at 07:25PM

Hi @AneeshU,
You're exactly right! For parallel reasoning questions, it is a common trap but the order of the sentences doesn't need to be exactly the same as long as the argument structure is the same and all of the premises and quantifiers match. That said, if we had two identical options except for the order of the sentences, we would choose the one that more closely matches. That scenario shouldn't really happen though.