Domingo orchestra- Strengthen question 700-800 levels

This topic has expert replies
Junior | Next Rank: 30 Posts
Posts: 14
Joined: Mon Mar 12, 2012 7:45 pm
Thanked: 1 times
Followed by:1 members
The young orchestral conductor Sabado Domingo is a true prodigy, able to recognize when any single instrument in his orchestra is even a bit out of tune. In a recent test, an orchestra played a hundred selections from different well-known classical pieces; in approximately half of the selections, exactly one instrument would be played slightly out of tune. In every instance in which an instrument was played out of tune, Domingo pointed out that the orchestra was out of tune, and correctly identified the instrument at fault.


Which of the following, if true, most strongly supports the conclusion of the argument above?

A. During the test, the orchestra was arranged in a traditional arrangement, similar to the arrangement in which they would be seated in a classical concert.

B. Domingo did not mistakenly label any of the orchestra's in-tune performances as out of tune.

C. Many of the musicians who intentionally played out of tune as part of the test have played perfectly in tune in every concert for the last ten years.

D. The instruments played out of tune were all played at a pitch exactly one half-step lower than the true pitch.

E. Because the test was performed in an empty concert hall, the acoustics of the concert hall differed somewhat from those of a concert hall populated by an audience.

Master | Next Rank: 500 Posts
Posts: 341
Joined: Sun Mar 25, 2012 6:59 pm
Thanked: 17 times
Followed by:4 members
GMAT Score:720

by ice_rush » Sat Jun 23, 2012 8:46 pm
I'd go with (B).

What is the source and OA?

User avatar
GMAT Instructor
Posts: 578
Joined: Tue Aug 25, 2009 6:00 pm
Thanked: 136 times
Followed by:62 members

by KapTeacherEli » Sat Jun 23, 2012 8:49 pm
Hi saviogmat!

Step 1: Identify the question type

This is a strengthen question. We can expect to find that the evidence is missing a piece necessary to properly support the conclusion; we should reaffirm that missing assumption.

Step 2: Untangle the stimulus.

The first sentence is the conclusion: Sabado Domingo can instantly recognize out-of-tune instruments. The clue that tells us this is the start of the second sentence, "in a recent test," since statistical and experimental data is usually evidence.

In this case, the evidence seems strong: Domingo perfectly ID'd every out of tune instrument in 100 tests. But does this support this conclusion that he can perfectly recognize instruments? Well, there's a sure way to guarantee his perfect result: declare every instrument in every orchestra out of tune! You'll never miss an out-of-tune instrument using this strategy!

This is actually a pretty classic GMAT set-up. Medical tests, warning alarms, and experiments can often confuse "false positives" with "false negatives." Low instance of both is necessary for accuracy. So, since we know that Domingo never has a false negative, the assumption this argument makes is:

"There were few or no false positives that cast doubt on Sabado Domingo's accuracy."

Step 3: Predict

This is a strengthen question, so we need a choice that supports our prediction. It's hard to imagine any roundabout way to do this, so it's likely that the correct answer will just restate the assumption as fact.

Step 4: Evaluate the answer choices

Prediction in hand, we can go straight to the correct answer: (B)
Eli Meyer
Kaplan GMAT Teacher
Cambridge, MA
www.kaptest.com/gmat

ImageImageImage

Newbie | Next Rank: 10 Posts
Posts: 6
Joined: Fri Jun 22, 2012 12:57 am
Location: Bangalore, India
Thanked: 2 times

by Chandra Gurrum » Sat Jun 23, 2012 10:24 pm
It was stated that Domingo pointed out correctly in every instance the instrument was played out of tune. It didn't mention how he reacted when the instrument was played in-tune. When the instrument was played in-tune and he mistakenly pointed out that it was out of tune, then this will undermine the conclusion.
Option B states how he reacted during in-tune performance and hence correct.

Senior | Next Rank: 100 Posts
Posts: 53
Joined: Sat Jul 17, 2010 3:56 am
Thanked: 1 times

by mourinhogmat1 » Sat Jun 23, 2012 10:29 pm
The way I looked at it was hit rates. The correct answer would address that. Hit rate = # of out of tuned instruments that were identified/ # of actually out of tune instruments. Only B answers the hit rates

Junior | Next Rank: 30 Posts
Posts: 14
Joined: Mon Mar 12, 2012 7:45 pm
Thanked: 1 times
Followed by:1 members

by saviogmat » Sun Jun 24, 2012 8:19 am
Thanks everyone. The OA is B.

Source: Manhattan GMAT.

Eli, your explanation really made sense. Thanks for clarifying my query

User avatar
Master | Next Rank: 500 Posts
Posts: 307
Joined: Wed Feb 22, 2012 9:45 pm
Thanked: 12 times
GMAT Score:700

by Gaurav 2013-fall » Sun Jun 24, 2012 8:29 pm
IMO B
and I dont think it is a 700 level problem
May be a 550 level.
Let me tell you something you already know. The world ain't all sunshine and rainbows. It is a very mean and nasty place and it will beat you to your knees and keep you there permanently if you let it. You, me, or nobody is gonna hit as hard as life. But it ain't how hard you hit; it's about how hard you can get hit, and keep moving forward. How much you can take, and keep moving forward. That's how winning is done. Now, if you know what you're worth, then go out and get what you're worth. But you gotta be willing to take the hit, and not pointing fingers saying you ain't where you are because of him, or her, or anybody. Cowards do that and that ain't you. You're better than that! (Rocky VI)