To become an expert on a musical instrument, a person must practice. I

Hi GMATNinja, Option C also provides the same reasoning as does Option B.
Can you help and elaborate?

Confused between option A and option B
What makes option B stronger than option A

To become an expert on a musical instrument, a person must practice. If people practice a musical instrument for three hours each day, they will eventually become experts on that instrument. Therefore, if a person is an expert on a musical instrument, that person must have practiced for at least three hours each day.

Which one of the following most accurately describes a flaw in the reasoning above?

(A) The conclusion fails to take into account that people who practice for three hours every day might not yet have reached a degree of proficiency that everyone would consider expert. The underlined part makes the option B better than A

(B) The conclusion fails to take into account that practicing for less than three hours each day may be enough for some people to become experts.


Stimulus states: To become an expert in music one must practice and if one practices music for 3 hours a day he/she will become an expert in music. Therefore if a person is an music expert he or she may have practiced music for atleast 3 hours for a day. The word at least is the clue here.

I've got one question about flaws. Maybe I lack some conceptual knowledge about Find the flaw questions, but nevertheless -
Don't Flaws in an Argument need to be internal? And doesn't a flaw only have to consider the given information?
Isn't assuming some musicians as gifted (which makes sense and probably is an obvious fact) external information?

Take another look at the conclusion of the passage:

The first piece of that sentence ("if a person is an expert on a musical instrument") places a condition on the conclusion. In other words, it limits the application of the second part of the sentence ("that person must have practiced for at least three hours each day"). So, the author is ONLY making an argument about people who are experts on musical instruments -- he/she has deliberately excluded any "non-experts" from the equation.

To assess the reasoning of the argument, we really only care about the actual argument that the author has made. What flaw does he/she make in drawing his/her exact conclusion from the evidence cited in the passage?

Here's (C):

This answer choice does not address the argument actually made in the passage -- the author concludes that experts must have practiced for at least three hours each day. The fact provided in (C) may (or may not) be true, but because (C) makes a statement about a completely different group of people (non-experts), it cannot be a flaw in the reasoning of the passage as it is written. Eliminate (C).


(A) can be eliminated for a reason similar to that we used to eliminate (C) above.

The author limits his/her conclusion to apply only to people who are already experts. Let's say that Joe picks up a bassoon practices for three hours each day for three days. After just a few days of practice, Joe is probably not an expert. So, it is entirely possible that "people who practice for three hours every day might not yet have reached a degree of proficiency that everyone would consider expert"!

However, can we say that the conclusion fails to take this into account? No, we can't -- the conclusion only applies to those already considered experts, so the fact that Joe is not yet considered an expert is not a flaw in the reasoning of the passage.

Contrast that with (B):

The author argues that if a person is an expert, that person MUST have practiced for at least three hours each day. In other words, there is only ONE path to expertise -- practicing at least three hours each day.

This conclusion is based on the evidence that if a person practices for three hours each day, that person will become an expert. Notice that this is only one POTENTIAL way that a person will become an expert, which leaves open the possibility of other paths to expertise. Maybe you're just a musical genius, or maybe you can sell your soul to the devil and become an expert fiddler after just an hour of practice.

The flaw in the reasoning of the passage is that the conclusion fails to account for these other ways to reach an expert level. By saying that all experts MUST have practiced for at least three hours a day, it (without justification) turns the potential path to expertise cited into the passage into the only path to expertise.

(B) is the correct answer.

I hope that helps!

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