GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 23 Jun 2018, 18:38

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Choi: All other factors being equal, children whose parents

Author Message
TAGS:

### Hide Tags

Manager
Joined: 17 Jul 2008
Posts: 229
Choi: All other factors being equal, children whose parents [#permalink]

### Show Tags

19 Jul 2008, 07:53
8
29
00:00

Difficulty:

95% (hard)

Question Stats:

30% (01:29) correct 70% (01:42) wrong based on 1308 sessions

### HideShow timer Statistics

Choi: All other factors being equal, children whose parents earned doctorates are more likely to earn a doctorate than children whose parents did not earn doctorates.
Hart: But consider this: Over 70 percent of all doctorate holders do not have a parent that also holds a doctorate.

Which of the following is the most accurate evaluation of Hart's reply?

(A) It establishes that Choi's claim is an exaggeration.
(B) If true, it effectively demonstrates that Choi's claim cannot be accurate.
(C) It is consistent with Choi's claim.
(D) It provides alternative reasons for accepting Choi's claim.
(E) It mistakes what is necessary for an event with what is sufficient to determine that the event will occur.

Could you explain in a detailed way please?

_________________

Please give kudos if you enjoy the explanations that I have given. Thanks

VP
Joined: 21 Jul 2006
Posts: 1455

### Show Tags

Updated on: 20 Jul 2008, 03:43
23
5
perfectstranger wrote:
2. Choi: All other factors being equal, children whose parents earned doctorates are more likely to earn a doctorate than children whose parents did not earn doctorates.
Hart: But consider this: Over 70 percent of all doctorate holders do not have a parent that also holds a doctorate.

Which of the following is the most accurate evaluation of Hart's reply?

A It establishes that Choi's claim is an exaggeration.
B If true, it effectively demonstrates that Choi's claim cannot be accurate.
C It is consistent with Choi's claim.
D It provides alternative reasons for accepting Choi's claim.
E It mistakes what is necessary for an event with what is sufficient to
determine that the event will occur.

Could you explain in a detailed way please?

Ahh, now I can see why option C is the answer.

Since Choi said "more likely", it means that he is open to the suggestion that his claim may not happen. So when Hart is saying that Choi's claim didn't happen, well it is still aligned to Choi's claim because Choi never claimed that his expectation WILL happen or 100% certain. Choi is aware that he could be wrong as well. Maybe that's what it is. The more extreme is Choi's argument, the easier you can argue that Choi is wrong if your claim is true. However, the more mild is Choi's argument, the more difficulty you will face in saying that Choi was wrong. Because when the argument or conclusion is mild, you're including the other possibilities for your conclusion not to be true in a more subtle way. so when Hart told Choi that he was wrong, well Choi did include that possibility by giving a mild conclusion.

Even If I say that I have a 99% chance that I will pass an exam, even if I fail, my claim is still consistent because I left 1% possibility that I could fail and that's what happened. Had I said that I am 100% sure that I will pass, but then I failed, THEN my claim would be inconsistent or wrong!

Option E's logic is reversed from what really happened. Option E says that Hart understood Choi's claim to be a possibility rather than certainty, something that is completely opposite because Hart actually thought that Choi was certain about Choi's claim.

Originally posted by tarek99 on 19 Jul 2008, 15:39.
Last edited by tarek99 on 20 Jul 2008, 03:43, edited 17 times in total.
GMAT Tutor
Joined: 24 Jun 2008
Posts: 1345

### Show Tags

19 Jul 2008, 23:28
5
3
I only agree with mbawaters above.

The key to the problem is not that Choi and Hart are talking about different groups of people. Choi is also talking about people who earn doctorates; when he says 'are more likely to earn doctorates', this does not refer to an event in the future.

Hart also does not confuse necessary and sufficient conditions in his response. What Hart says is neither necessary nor sufficient to refute Choi. E is not correct.

The point is that Hart's argument does not contradict Choi's statement. If only a small number of parents hold doctorates, both Choi and Hart could be entirely correct. That is, their statements are perfectly consistent, in the intended sense of being 'logically consistent': they can both be true. C.

"2. Choi: All other factors being equal, children whose parents earned doctorates are more likely to earn a doctorate than children whose parents did not earn doctorates.
Hart: But consider this: Over 70 percent of all doctorate holders do not have a parent that also holds a doctorate."
_________________

GMAT Tutor in Toronto

If you are looking for online GMAT math tutoring, or if you are interested in buying my advanced Quant books and problem sets, please contact me at ianstewartgmat at gmail.com

Intern
Joined: 26 Aug 2010
Posts: 1

### Show Tags

Updated on: 28 Aug 2010, 13:27
5
1

Assume that of a population of 100 parents, 10% have children with PhDs. So there are 10 PhDs. (10% is reasonable because the number of PhD in a population is low, probably around 2%)

Hart's statement tells us that 3 of the 10 have parents who hold Phds and the other 7 do not.

Thus Hart's statement proves Choi's statement (that PhDs are more likely to have children that have PhDs)

The chance that a person without a PhD has a child with a PhD is 7/90

The chance that a person with a PhD has a child with a PhD is 3/10

* by the way, when one say something is more likely, it means that past data has shown that this claim to be true. i.e if I said, it is more likely that hurricanes follow a period of hot weather, it means that hurricanes have occurred more often after a period of hot weather than after a period of normal weather.

Originally posted by ashah20 on 26 Aug 2010, 16:31.
Last edited by ashah20 on 28 Aug 2010, 13:27, edited 4 times in total.
Kaplan GMAT Instructor
Joined: 25 Aug 2009
Posts: 640
Location: Cambridge, MA

### Show Tags

30 Aug 2010, 14:52
perfectstranger wrote:
Choi: All other factors being equal, children whose parents earned doctorates are more likely to earn a doctorate than children whose parents did not earn doctorates.
Hart: But consider this: Over 70 percent of all doctorate holders do not have a parent that also holds a doctorate.

Which of the following is the most accurate evaluation of Hart's reply?

(A) It establishes that Choi's claim is an exaggeration.
(B) If true, it effectively demonstrates that Choi's claim cannot be accurate.
(C) It is consistent with Choi's claim.
(D) It provides alternative reasons for accepting Choi's claim.
(E) It mistakes what is necessary for an event with what is sufficient to determine that the event will occur.
HI Perfectstranger,

The bolded part is the key. Choi is making a hypothetical statement--if all else is equal, then having parents is an advantage. Hart is making an empirical statement: he is discussing reality, in which all else isn't equal, and so his final results differ. This is entirely consistent with Choi's claim, since Hart is shifting the scope of the discussion from the theoretical to the practical.

Note that, in addition to the scope shift, a number/percent error may be present in Hart's claim. Take a look at ashah20's post for a great explanation. As is often the case on the GMAT, there are multiple ways to get to the correct solution!
_________________

Eli Meyer
Kaplan Teacher
http://www.kaptest.com/GMAT

Prepare with Kaplan and save \$150 on a course!

Kaplan Reviews

Kaplan GMAT Instructor
Joined: 25 Aug 2009
Posts: 640
Location: Cambridge, MA
Re: Choi: All other factors being equal, children whose parents [#permalink]

### Show Tags

Updated on: 31 Aug 2013, 13:53
1
dpvtank wrote:

Ok folks, I understand why option C is correct. I was struggling between C & E.

I had picked E, but when I tried to understand why it was wrong...I had no idea. Here's why: I have no idea what option E is saying! The whole necessary/sufficient thing is really making my head buzz. It seems like LSAT terminology, because I haven't really come across any questions with that sort of terminology in OG12 or VOG2.

Which of the following sentence makes more sense:

Joey does not have nails or a hammer, so Joey cannot build a house.
Joey has nails and a hammer, so Joey can build a house.

The first one is solid but the second one seem iffy, right? Well, that's what E is saying. To build a house, you must have a hammer and nails; they are necessary tools to complete the process. But in addition to hammer and nails, you need lumber, paint, ladders, screws, electrical wiring, pipes, and siding. A hammer and nail are not sufficient to build a house, not by a long shot! And the second statement above mistakes a necessary condition for a sufficient one, so it is flawed.

However, as discussed above, neither Hart nor Choi make such a flawed premise; in fact, both of their statements are logically consistent. So choice (E), which describes a common reasoning flaw not present in this prompt, is wrong.
_________________

Eli Meyer
Kaplan Teacher
http://www.kaptest.com/GMAT

Prepare with Kaplan and save \$150 on a course!

Kaplan Reviews

Originally posted by KapTeacherEli on 31 Aug 2012, 14:04.
Last edited by KapTeacherEli on 31 Aug 2013, 13:53, edited 1 time in total.
Kaplan GMAT Instructor
Joined: 25 Aug 2009
Posts: 640
Location: Cambridge, MA
Re: Choi: All other factors being equal, children whose parents [#permalink]

### Show Tags

31 Aug 2012, 14:07
OldFritz wrote:
Actually, Choice C is not reasonably waterproof.

Here's why:
We know that over 70% of PhD holders were not sired by PhD holders. This percentage/proportion could range from more than 70% up to 100%. Testing the extreme values of this range, we see that the percentage of PhD holders whose parents were PhD holders themselves can range from less than 30% to even 0%.

Applying these figures (which we deduced from Hart's statement) to the claim made by Choi, we can say that if 30% of PhD holders were born to parents who are PhD holders themselves, then we can reasonably say that, assuming the parents who are PhD holders are less than 30% of the population, then their kids are definitely more likely to hold a PhD.
This interpretation IS consistent with Hart's claim.

Conversely, if 100% of PhD holders were born to parents who are not PhD holders themselves (or 0% of PhD holders were born to parents who are PhD holders), then we can reasonably say that, assuming the parents who are PhD holders are ANY percent of the PhD holders of their "generation", then their kids are NOT any more likely to hold a PhD--in fact they will be less likely to have a PhD.
This interpretation IS NOT consistent with Hart's claim.

This makes C a rather unconvincing answer.

Kaplan could have given a "better" or stronger answer (statement from Hart) that would have been consistent with Choi's claim if they had written that, say, "More than 5% of PhD holders were born to PhD holding parents". Even so, such a response would require us to assume the proportion of PhD holders of the "parental generation" etc.

Point is, if the given percentages are not well-tested by the test makers, it can open a can of worms brimming with a myriad, slimy test cases of proportions and percentages that can unintentionally lead to contradictory cases.

Cheers,
Der Alte Fritz.
Hi Fritz,

"Consistent" does not mean "means the same thing as." It just means "does not contradict." And as you've pointed out in your reasoning, it is entirely possible (though by no means guaranteed) that Hart and Choi are both completely right! Their statements are consistent.

Regards,
_________________

Eli Meyer
Kaplan Teacher
http://www.kaptest.com/GMAT

Prepare with Kaplan and save \$150 on a course!

Kaplan Reviews

Kaplan GMAT Instructor
Joined: 25 Aug 2009
Posts: 640
Location: Cambridge, MA
Re: Choi: All other factors being equal, children whose parents [#permalink]

### Show Tags

31 Aug 2012, 21:40
OldFritz wrote:
Dear Eli,

From which part of what I wrote are you deducing that I am interpreting "consistency" as "the same thing as"? My point is, and remains, simple. Though option C might pass muster (perhaps barely so), it is exposed to interpretations (diligently explained in my previous post) that can make Hart's statistics consistent (not the "same thing as", mind you) with Choi's position in some cases and inconsistent in others.

Maybe you should consider taking time to read what I wrote if you care to respond, sir, instead of using turning to the good old "Strawman."

Cheers,
Der alte Fritz.

Posted from my mobile device
Hi Fritz,

Sorry if I'm not understanding what you are saying. But if Choi's position is "in some cases" inconsistent with Hart's, then the two statements are certainly "consistent." When discussing logical arguments, "consistent" means simply "could both be true," and "inconsistent" means "cannot both be true." Since there are circumstances in which Hart and Choi's statements could both be true (even if in many--or most!--cases, they are not both true), the statements are consistent and (C) is correct. I hope this explains what I meant!

Regards,
_________________

Eli Meyer
Kaplan Teacher
http://www.kaptest.com/GMAT

Prepare with Kaplan and save \$150 on a course!

Kaplan Reviews

Kaplan GMAT Instructor
Joined: 25 Aug 2009
Posts: 640
Location: Cambridge, MA
Re: Choi: All other factors being equal, children whose parents [#permalink]

### Show Tags

02 Sep 2012, 14:17
mourinhogmat1 wrote:
I agree with most replies here. This question is definitely not "GMAT" like. The concepts of sufficiency and necessity are not explained anywhere in Official Guides.
There is no way a test taker is going to be aware of this just by reading the official guide or the concepts mentioned in it.

Off the top of my head, I have no idea what defines a condition for necessity and what is a condition for sufficiency?

It is unfair to test folks on these concepts without prior knowledge. I believe Kaplan assumes people have this prior knowledge.
Hi mourinhogmat,

"Necessity versus Sufficency" is tested far more often by the LSAT than on the GMAT. However, it is not something analogous to, say, sines and cosines on the Quant section (which will never be tested because they can't be solved intuitively or with "common knowledge.) It is a common logical flaw in life, along with "proportion vs. number" and "causation vs. correlation," and so it's fair game for the GMAT to test!
_________________

Eli Meyer
Kaplan Teacher
http://www.kaptest.com/GMAT

Prepare with Kaplan and save \$150 on a course!

Kaplan Reviews

Retired Moderator
Joined: 16 Jun 2012
Posts: 1079
Location: United States
Re: Choi: All other factors being equal, children whose parents [#permalink]

### Show Tags

14 Jun 2013, 02:18
12
1
Tough question. IMO, C is correct.

The question is: Which of the following is the most accurate evaluation of Hart's reply
So we need to find an answer that must be true for what Hart replied. Don't be simply lured by signal words such as However, but, what more....... Make sure you understand the full context of the argument.

Choice: Children + parents earned doctorates ==> more likely to earn a doctorate than other children.
Hart: Over 70% of all doctorate holders do not have a parent also holds a doctorate.

Example:
There are 500 children,
30 children who have parent also hold doctorate. 20 children will earn doctorate ==> probability = 20/30 = 67%
570 other children, only 80 children will earn doctorate ==> probability = 70/570 = 14%

Clearly, Although 80% all doctorate holders do not have a parent that also holds a doctorate. they are less likely to earn a doctorate than children whose parents have doctorates (14% VS 67%)

==> Hart's reply is consistent with Choi.

How about other options. Why they are wrong?

(A) It establishes that Choi's claim is an exaggeration.
Wrong. Hart did not say Choi exaggerated.

(B) If true, it effectively demonstrates that Choi's claim cannot be accurate.
Wrong. Even Hart's reply is true, Choi's claim can also be true.

(C) It is consistent with Choi's claim.
Correct.

(D) It provides alternative reasons for accepting Choi's claim.
Wrong. There is no alternative reason.

(E) It mistakes what is necessary for an event with what is sufficient to determine that the event will occur.
Wrong. There are not necessary condition and sufficient condition in the argument. Moreover, Hart's reply is actually not a sufficient condition for Choi's claim.

Hope that helps.
_________________

Please +1 KUDO if my post helps. Thank you.

"Designing cars consumes you; it has a hold on your spirit which is incredibly powerful. It's not something you can do part time, you have do it with all your heart and soul or you're going to get it wrong."

Chris Bangle - Former BMW Chief of Design.

Intern
Joined: 24 Jul 2013
Posts: 2
Re: Choi: All other factors being equal, children whose parents [#permalink]

### Show Tags

Updated on: 30 Jul 2013, 10:48
1
ramanujanu wrote:
I do not quiet get this . If 70% of doctrates do not have doctorate parents ... we are to be bothered about the 30% which have doctorate parents . now the question is as to what percentage of the doctorate parents have doctorate kids(what %age i.e). The data in the question does not address this point at all . I found the information irrelevent.

Where did i go wrong ?

arvindsekar wrote:
plumber250 wrote:
Hi Ramanujanu,

I think you've sort of answered your own question. You say it's 'irrelevant' - but you could also say that it's consistent - you've said no where that it contradicts the info given by Choi - so both can be true - so it's consistent. (n.b we're not looking for 'supports' or 'strengthen' we just have to be able to hold both arguments together)

Then go through the other choices and you'll soon see the others are all impossible (reasons given by pqhai).

Tough one.

James

Sorry for posting so late.
I din't quite understand. Though the 2 statements are consistent to a certain degree, I feel that Hart's claim is more exaggerated than consistent i.e., Hart says it is MORE LIKELY, which I assume 50% - 70% cases. But as per Choi's statement, Hart's reasoning is only 30% true !! .. What am I missing / misunderstood here.

Regards,
Arvind

It seems that pqhai has the right idea, but this is not how I came to the correct answer.

Lets try looking at it this way:

"Choi: All other factors being equal, children whose parents earned doctorates are more likely to earn a doctorate than children whose parents did not earn doctorates.

Hart: But consider this: Over 70 percent of all doctorate holders do not have a parent that also holds a doctorate."

Example: Out of 125 parents, 25 hold PhD's and 100 do not

Lets say each parent has one child, and of those 125 children, 85 earn PhD's. If 70% of those 85 PhD holders are children of parents that do not have PhD's, this means that only 60/100 children whose parents do not have PhD's obtain a PhD. Thus, although 70% of PhD holders as Hart claims do not have parents with PhD's, 70% only constitutes 60% of the total population of children who have parents without PhD's. Thus, children of parents that do not have PhD's have a 60% chance of earning a PhD.

It then becomes clear that although the children of PhD holders constitute only 30% of the total number of PhD holders, it is clear that 30% of the 85 children who do earn a PhD from the pool of 125 is equal to 25, which means that 100% of the children of PhD holders earn a PhD in this particular case.

Thus, Hart's claim s consistent with Choi's because even if 70% of children that earn PhD's come from a non-PhD holding household, it is still only 60% of those children that earn a PhD in contrast to 100% of children who's parents have PhD's and constitute only 30% of the total PhD holding population. Thus, C is clearly the best answer.

It seems that the argument is based on the fact that there are far many more parents without PhD's than those with PhD's, thus the use of " All other factors being equal" by Choi seems to be a clue into this fact. "All things being equal" is an idiom that means"if things stay the way they are," a reference to the actual numbers on which the percentages are based and which to an American English speaker may seem more clear. So part of the difficulty of this question seems to derive from understanding this idiom as a clue into the fact that there are far fewer PhD's than people without PhD's because it is only in that context that the play of percentages makes sense. Therefore, Hart's claim is consistent with Choi's.

I hope this clarifies,

Albert

Please visit w w w . g m a t q u e s t i o n s . o r g for help with this and other types of questions with 200+ FREE practice questions with step-by-step expert video tutorials (launching Monday, 7/29/13!)

Originally posted by AlbertCA on 26 Jul 2013, 09:46.
Last edited by AlbertCA on 30 Jul 2013, 10:48, edited 2 times in total.
Princeton Review Representative
Joined: 17 Jun 2013
Posts: 160
Re: Choi: All other factors being equal, children whose parents [#permalink]

### Show Tags

30 Jul 2013, 06:11
1
This question is based on statistics so you have to be aware that percents depend on knowing the actual numbers.

Choi says if your parent has a doctorate you are more likely than the rest of the population to earn a doctorate. Hart claims that 70% of doctorate holders do not have a parent with a doctorate. The test writers want you to believe that more likely is related to the 70% but in fact those two are not related numbers. Once you understand that the issue is with the percents then it is time to eliminate wrong answers.
dhruvd wrote:
Choi: All other factors being equal, children whose parents earned doctorates are more likely to earn a doctorate than children whose parents did not earn doctorates.

Hart: But consider this: Over 70 percent of all doctorate holders do not have a parent that also holds a doctorate.

Which of the following is the most accurate evaluation of Hart's reply?

(A) It establishes that Choi's claim is an exaggeration.Because the 70% and the most likely are not directly related this cannot be true
(B) If true, it effectively demonstrates that Choi's claim cannot be accurate.This is wrong because if only 100 parents have doctorate degrees then only 100 children are more likely to get them and if 1000 people get doctorate degrees then both claims are true.
(C) It is consistent with Choi's claim.This is the best answer because there are numbers for which both statements are true, thus the claim is consistent (see answer B for numbers)
(D) It provides alternative reasons for accepting Choi's claim.Hart's argument attempts to discredit Choi, therefore it does not provide additional information to accept the claim
(E) It mistakes what is necessary for an event with what is sufficient to determine that the event will occur.Choi does not mention what is necessary to get a degree, or what is sufficient to get a degreeonly what makes a degree more likely, therefore this statement is not true

_________________

Special offer! Save \$250 on GMAT Ultimate Classroom, GMAT Small Group Instruction, or GMAT Liveonline when you use the promo code GCVERBAL250. Or, save \$150 on GMAT Self-Prep when you use the code GCVERBAL150. Enroll at www.princetonreview.com

Kaplan GMAT Instructor
Joined: 25 Aug 2009
Posts: 640
Location: Cambridge, MA

### Show Tags

31 Aug 2013, 13:57
vaibhavsharma wrote:
Here the key word "likely to be " is playing the vital role in deciding option for answer . likely to be means that first person is always open to his argument whether it is right or wrong rather than claiming it and second person is putting data to open discussion in above argument so it becomes consistent with fist argument

Hence C ,however very patchy question but to be aware about the same pattern next time
Hi vaibhavsharma,

As we discussed earlier, there is a different key phrase that you're missing--"likely to be" isn't really the central phrase.

The most important part of the prompt is the phrase "all else being equal." As soon as we see that, we know that one speaker is discussion hypothetical situations, and the other is discussing (unequal) reality. The two discussions are completely orthogonal to one another, and are therefore consistent (meaning not that they say the same thing, but rather, that they could both be correct at the same time)

Hope this helps!
_________________

Eli Meyer
Kaplan Teacher
http://www.kaptest.com/GMAT

Prepare with Kaplan and save \$150 on a course!

Kaplan Reviews

Manager
Joined: 07 May 2012
Posts: 66
Location: United States
Re: Choi: All other factors being equal, children whose parents [#permalink]

### Show Tags

16 Oct 2013, 13:55
2
1
Choi : childrens with doctoral parents more likely to become doctors than childrens with non doctoral parents

Lets say there are -
10 doctoral parents -(50% likely that their children will be doctors)- out of which 5 children doctors.
1000 non doctoral parents - 10% likely - 100 children doctor

total doctoral children = 105
Doctoral children with doctor parents = 5
Doctoral children with non doctor parents = 100

Hart: over 70% doctoral children have parents with no doctoral .

considering above highlighted data -
100/105 is the ratio/percentage of doctoral children with non-doctoral parent ( which is consistent with Hart - ratio is way over 70%).

This is more like a weighted average problem in quant.

Hence Hart's statement is consistent with Choi's .
-Jyothi
_________________

Jyothi hosamani

EMPOWERgmat Instructor
Joined: 25 Jul 2014
Posts: 14
Re: Choi: All other factors being equal, children whose parents [#permalink]

### Show Tags

18 Aug 2014, 10:27
hapless12 wrote:
Why C.
It is against , not consistent. I am still not sure after reading the explanations. Not convinced. I chose E
" But consider this:" clearly shows that she is going to contradict.

pls guide

Hi hapless12,

GMAT questions (and LSAT style questions like this) are always structured to have a twist to them. The twist here is that set of contrast words you mentioned. The contrast words don't matter though because is what Hart says actually inconsistent with what Choi says? No.

What both Choi and Hart say could coexist, therefore we know for a fact that those two statements are consistent.

Its also important to note here that consistency doesn't mean supportive. It just means that the two statements can both be true, or in other words, that they don't disprove each other.

Much more to the bigger picture though, this is an LSAT style question by the way. Of all of the publicly released GMAC material, not a singe question has is remotely similar to this type. Questions like this do occur on the LSAT, however. That's why although certain LSAT questions can be helpful for the GMAT, many would be irrelevant for the GMAT. Its important to use caution when using LSAT or GRE practice questions to prepare for the GMAT. Each test has its own flavor.
_________________

Allen T.
http://www.empowergmat.com

EMPOWERgmat GMAT Club Page, Study Plans, & Discounts

Director
Joined: 04 Jun 2016
Posts: 609
GMAT 1: 750 Q49 V43
Choi: All other factors being equal, children whose parents [#permalink]

### Show Tags

14 Jun 2016, 01:01
A very cheap algebra data sufficinecy word problem, disguised as critical thinking problem.
Answer should not take more than a minute to reveal itself:- BY THE WAY THE CORRECT ANSWER IS C

THINGS YOU SHOULD KNOW BEFORE SOLVING THIS QUESTION:-
LESS LIKELY MEANS PROBABILITY IS 49% OR LESS THAN 49%
EQUALLY LIKELY MEANS PROBABILITY IS 50%-50%
MORE LIKELY MEANS PROBABILITY IS 51% OR MORE THAN 51 %

To start in a fair an unbiased manner :-
Assume there are 1000 parents.
500 parents have Phd. 500 DO NOT have PhD (Do not skew this ratio. Even though any ratio would give you the correct answer, you must solve these kind of question by assuming both sides are equal A=B and then you will not have to test other two cases A<B or A>B. After seeing the solution , try to solve this problem with any ratio you want and you will still get the right answer)

NOW STARTS THE REAL QUESTION (ALGEBRA + PROBABILITY)
WE WILL SOLVE ALGEBRA FIRST AND THEN MOVE TO PROBABILITY.

A) All other factors being equal, children whose parents earned doctorates are more likely to earn a doctorate than children whose parents did not earn doctorates.
Parents with PHD = 500
More likely = 51 %
Children having PHD = 51 % of 500 = 255 PHD

B) Over 70 percent of all doctorate holders do not have a parent that also holds a doctorate.
Keep the term all doctorate in mind .
ALL doctorate means = (all kids= all whose parents have phd = 255)AND(kids whose parents have no phd=x)
The percentage of kids whose parents don't have phd is not given to us in the question stem. but we can easily find it
The percentage of phd kids whose parents don't have phd is x % of 500 (remember 500 parents don't have phd)= x% of 500 = (x/100)of 500 = 5x

now you know
Over 70 percent of all doctorate holders do not have a parent that also holds a doctorate.
70 % (255 +5x)=do not have parent that also holds a doctorate.
or
70 % (255 +5x)=non phd parent (how many non phd parents are there = 500 non phd parents)
70 % (255 +5x)=500
70/100 (255 +5x)=500
7/10 (255 +5x)=500
7 (255 +5x)=500*10 (we took 10 to the right)
7(255 +5x)=5000
1785+35x=5000
35x=5000-1785
35x=3215
x=3215/35
x=92
There are 92 kids who have phd but whose parents don't have phd.

NOW COMES THE PROBABILITY PART :-

92 KIDS HAVE PHD BUT THIER 500 PARENTS HAVE NO PHD
PROBABILITY OF KID HAVING PHD BUT PARENTS HAVING NO PHD = 92/500 = 18.4 %

255 KIDS HAVE PHD AND THIER 500 PARENTS HAVE PHD (We derived this as the very beginning of the question. remember the more likely to have phd clause.)
PROBABILITY OF KID HAVING PHD AND PARENTS HAVING PHD = 255/500 = 51%

This is what Hart said in her argument but in a different way.

Which of the following is the most accurate evaluation of Hart's reply?
(C) It is consistent with Choi's claim.

Choi: All other factors being equal, children whose parents earned doctorates are more likely to earn a doctorate than children whose parents did not earn doctorates.
Hart: But consider this: Over 70 percent of all doctorate holders do not have a parent that also holds a doctorate.

Which of the following is the most accurate evaluation of Hart's reply?

(A) It establishes that Choi's claim is an exaggeration.
(B) If true, it effectively demonstrates that Choi's claim cannot be accurate.
(C) It is consistent with Choi's claim.
(D) It provides alternative reasons for accepting Choi's claim.
(E) It mistakes what is necessary for an event with what is sufficient to determine that the event will occur.

_________________

Posting an answer without an explanation is "GOD COMPLEX". The world doesn't need any more gods. Please explain you answers properly.
FINAL GOODBYE :- 17th SEPTEMBER 2016. .. 16 March 2017 - I am back but for all purposes please consider me semi-retired.

GMAT Club Verbal Expert
Joined: 20 Nov 2016
Posts: 274
Re: Choi: All other factors being equal, children whose parents [#permalink]

### Show Tags

08 Jan 2018, 14:42
2
chesstitans wrote:
GMATNinja, broall
this kind of question is really rare in gmat and this question is not from LSAT. Do you think official exam will ever include this question?

I wouldn't worry about this unofficial question too much. Choice (C) could be accurate (depending on the numbers), but this is not the type of thing you would see on the actual test.
_________________
Re: Choi: All other factors being equal, children whose parents   [#permalink] 08 Jan 2018, 14:42
Display posts from previous: Sort by