GMATPrep - CR - First-time computer buyers buying PXC home

[phoenix.rkchr]

First-time computer buyers buying PXC home computers typically buy models that cost much less and have a smaller profit margin per computer than do PXC computers bought by people replacing their computers with more powerful models. Last year PXC's profits from computer sales were substantially higher than the previous year, although about the same number of PXC computers were sold and the prices and profit margins for each computer model that PXC sells remained unchanged.

If the statements above are true, which of the following is most strongly supported by them?

A) PXC's competitors raised the prices on their computers last year, making PXC computers more attractive to first-time computer buyers.

B) The number of people buying PXC computers who also bought PXC computer-related products, such as printers, was larger last year than the previous year.

C) Among computer buyers who bought a PXC computer to replace their existing computer, the proportion who were replacing a computer made by a competitor of PXC was greater last year than the previous year.

D) The proportion of PXC computers bought by first-time computer buyers was smaller last year than the previous year.

E) PXC's production costs for its computers were lower last year than they had been the previous year.

The CR is from GMATPrep.
OA - D

Could any one explain what is the issue in C?

[debmalya.dutta]

C) Among computer buyers who bought a PXC computer to replace their existing computer, the proportion who were replacing a computer made by a competitor of PXC was greater last year than the previous year.

Though in the real world it would have made perfect sense ..however in the context of the statements provided , nothing has been mentioned about replacing computer made by a competitor.

This is an Inference . Draw Conclusion question. So based it on the facts mentioned in the statements as opposed to getting in to the picture new information

[phoenix.rkchr]

Hi debmalya.dutta,

Thanks for the explanation.
Now, it is clear to me.

Thanks

[tim]

Thanks for the explanation, debmalya.dutta

[nehajadoo]

Why are A and E wrong? for the same reason as C? that D is simply the most direct answer?

[RonPurewal]

Why are A and E wrong? for the same reason as C? that D is simply the most direct answer?

it appears that you are misunderstanding what's going on in the problem.

this is NOT an "explain the discrepancy" problem; in that sort of problem, you have to choose which one of five hypothetical situations -- if the situations are assumed to be true -- would best explain the stated facts.

rather, this is a "draw the conclusion" problem (i.e., you need a statement that is "supported BY" the facts).
this means that you have to be able to PROVE the statement given, beyond any reasonable objection. in other words, basically, you have to be 100% sure (or at least 99.99% sure, anyway) that the statement is true.

since that's a rather stringent criterion, it follows that you can't PROVE statements about things that just aren't discussed in the first place. therefore, in these problems, any statement about a topic that isn't in the original passage is WRONG.
(again, note the HUGE contrast with "explain the discrepancy" problems, in which you must pick a statement that lies outside the scope of the original passage.)

(a) the passage mentions absolutely nothing about competitors' prices, so you can't PROVE this statement.
in fact, you can't produce any sort of argument for this statement at all -- it's random wild guessing.

(b) the passage mentions absolutely nothing about non-computer products, so you can't PROVE this statement.
in fact, you can't produce any sort of argument for this statement at all -- it's random wild guessing.

(c) the passage mentions absolutely nothing about the origin of the computers being replaced -- i.e., the only dichotomy mentioned is "replacing a new computer [from we-have-no-idea-where]" vs. "buying a first computer" -- so you can't PROVE this statement.
in fact, you can't produce any sort of argument for this statement at all -- it's random wild guessing.

(d) notice that this choice actually stays within the scope of the statements made in the passage. i.e., it doesn't bring in ANY outside topics.

(e) the passage mentions absolutely nothing about production costs, so you can't PROVE this statement.
in fact, you can't produce any sort of argument for this statement at all -- it's random wild guessing.

hope that helps. with this sort of approach, you'll probably find that this variety of problem is a lot more black-and-white than you had previously thought.

[chembeti_aravind]

C) Among computer buyers who bought a PXC computer to replace their existing computer, the proportion who were replacing a computer made by a competitor of PXC was greater last year than the previous year.

Though in the real world it would have made perfect sense ..however in the context of the statements provided , nothing has been mentioned about replacing computer made by a competitor.

This is an Inference . Draw Conclusion question. So based it on the facts mentioned in the statements as opposed to getting in to the picture new information

IMO, C is also a strong contender and the reason why we need to eliminate it is as follows:

C is a strong contender because it also tells us that there are more no. of sales of costly computers. But, we can eliminate this because the argument uses the word 'TYPICALLY' in the first statement, which means even first time buyers are also buying costly computers. This fact is reflected only in D but not in C.

[RonPurewal]

C is a strong contender because...

nope, (c) is completely irrelevant.

only one distinction matters in the argument: first-time computer buyers (who pay less) on one hand, and people who are replacing their computers (who pay more) on the other hand.

(c) is irrelevant to this distinction; it actually takes the second group (people who are replacing their computers) and divides it according to a criterion that doesn't matter, namely, the brand of computer that these people are replacing.
we don't care what brand of computer these people are replacing; we only care what brand they are buying to replace it. so (c) doesn't help.

[mindadze]

My understanding about (C) is that it is not wrong because it brings "outside" information to the problem. The Argument mentions that buyers of PXC computers who are replacing THEIR computers generate more profit. "THEIR" computers can also be computers made by PXC's competitor. So answer choice in my opinion falls into the scope of the Argument.

It is wrong simply because it says: "Among computer buyers who bought a PXC computer to replace their existing computer..." It sets a proportion between a) buyers who replace computers made by competitor of PXC and b) buyers who replace "other" computers. This proportion is irrelevant.

The relevant proportion is the one between a) first time buyers and b) buyers who replace computers. Answer choice relating to this proportion is (d).

[RonPurewal]

mindadze --
that's pretty much the idea, but you're saying basically what i already said in the post directly above yours.
are you perceiving some difference between the message in your post and the message in mine? if so, i'm not seeing the difference.

[mindadze]

I agree with you Ron, your previous there is not difference between my post and your's, which is directly above.

[messi10]

Hello,

What type of CR is this? Explain or Conclusion?

The wording of the question seems similar to a conclusion question but once you read the argument, it seems more like an explain question

Thanks

[RonPurewal]

Hello,

What type of CR is this? Explain or Conclusion?

The wording of the question seems similar to a conclusion question but once you read the argument, it seems more like an explain question

Thanks

in this case, we're talking about reasoning that works in either direction.
i.e., if you made a graph with "proportion of 1st-time buyers" on the x axis and "profits per unit" on the y axis, then you'd have a graph with an upward trend. therefore, you could reason in either of the following directions:
greater % of 1st time buyers --> lower profits per unit
or
lower profits per unit --> greater % of 1st time buyers.

so, in this problem, you can really think in either of those two ways.

what's most important, though, is just to understand the task at hand.
if you already know exactly how to reason through the question, DON'T classify the question!
the question classifications are, at best, a crude tool for separating questions according to major differences. however, they are no substitute for normal human reasoning"”and, if you already understand the nature of the task, then they are inferior to the reasoning process that already exists in your head.
they can be helpful if you are confused"”but you should try to use them only if you are confused.