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# GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn

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GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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Updated on: 27 Jul 2017, 08:05
11
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Question 1
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based on 1170 sessions

77% (02:40) correct 23% (03:00) wrong

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Question 2
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based on 1120 sessions

79% (01:12) correct 21% (01:25) wrong

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Question 3
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90% (01:08) correct 10% (01:37) wrong

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NEW PROJECT!: Back to basic => Give your explanation- Get Kudos Point for best explanation

Passage-12 GMATPrep RCs-Collection(Main article)
In the 1980's, astronomer Bohdan Paczynski proposed a way of determining whether the enormous dark halo constituting the outermost part of the Milky Way galaxy is composed of MACHO's (massive compact halo objects), which are astronomical objects too dim to be visible. Paczynski reasoned that if MACHO's make up this halo, a MACHO would occasionally drift in front of a star in the Large Magellanic Cloud, a bright galaxy near the Milky Way. The gravity of a MACHO that had so drifted, astronomers agree, would cause the star's light rays, which would otherwise diverge, to bend together so that, as observed from Earth, the star would temporarily appear to brighten, a process known as microlensing. Because many individual stars are of intrinsically variable brightness, some astronomers have contended that the brightening of intrinsically variable stars can be mistaken for microlensing. However, whereas the different colors of light emitted by an intrinsically variable star are affected differently when the star brightens, all of a star's colors are equally affected by microlensing. Thus, if a MACHO magnifies a star's red light tenfold, it will do the same to the star's blue light and yellow light. Moreover, it is highly unlikely that a star in the Large Magellanic Cloud will undergo microlensing more than once, because the chance that a second MACHO would pass in front of exactly the same star is minuscule.
1. The passage is primarily concerned with

A. outlining reasons why a particular theory is no longer credited by some astronomers
B. presenting data collected by a researcher in response to some astronomers' criticism of a particular line of reasoning
C. explaining why a researcher proposed a particular theory and illustrating how influential that theory has been
D. showing how a researcher's theory has been used to settle a dispute between the researcher and some astronomers
E. describing a line of reasoning put forth by a researcher and addressing a contention concerning that line of reasoning

2. According to the passage, Paczynski's theory presumes that if MACHO's constituted the Milky Way's dark halo, occasionally a MACHO would

A. drift so as to lie in a direct line between two stars in the outer Milky Way
B. affect the light rays of a star in the Large Magellanic Cloud with the result that the star would seem for a time to brighten
C. become obscured as a result of the microlensing of a star in the Large Magellanic Cloud
D. temporarily increase the apparent brightness of a star in the Large Magellanic Cloud by increasing the gravity of the star
E. magnify each color in the spectrum of a star in the Large Magellanic Cloud by a different amount

3. It can be inferred from the passage that which of the following would constitute the strongest evidence of the microlensing of a star in the Large Magellanic Cloud?

A. The brightness of such a star is observed to vary at irregular intervals.
B. The brightening of such a star is observed to be of shorter duration than the brightening of neighboring stars.
C. The red light of such a star is observed to be brighter than its yellow light and its blue light.
D. The red light, yellow light, and blue light of such a star are observed to be magnified temporarily by the same factor.
E. The red light of such a star is observed to have increased tenfold.

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Originally posted by PiyushK on 12 Aug 2014, 04:46.
Last edited by hazelnut on 27 Jul 2017, 08:05, edited 4 times in total.
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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09 Aug 2015, 14:49
22
5
I watch "thursdays with Ron" and Ron says about interesting way of solving main idea questions in highly technic RC passages. He recommend to omit all text except key words that change flow of the passage.

Here is my try to do that on this passage:

1) Bohdan Paczynski proposed a way of determining .... [some new theory]
2) Paczynski reasoned that .... [support of theory]
3) Because ... some astronomers have contended that .... [because of something this theory was argue by others astronomers]
4) However .... [author of passage doesn't agree with astronomers]
5) Thus .... [theory is good because of previous word "however"]
6) Moreover .... [and here is one more reason why theory is good]

So we see that first two parts is about new theory, then some arguing and last half of passage support theory.

The passage is primarily concerned with
A. outlining reasons why a particular theory is no longer credited by some astronomers
this answer miss parts 4-6. Incorrect

B. presenting data collected by a researcher in response to some astronomers' criticism of a particular line of reasoning
theory was created before critisms

C. explaining why a researcher proposed a particular theory and illustrating how influential that theory has been
We have only fact of theory and not reasons why it was created. Incorrect

D. showing how a researcher's theory has been used to settle a dispute between the researcher and some astronomers
theory procreate a critism so it can't be used for settling of this dispute. Incorrect

E. describing a line of reasoning put forth by a researcher [1-2 parts]
and addressing a contention concerning that line of reasoning [3-6 parts]

Correct

So with such technic we can solve main idea question even if completely didn't understand topic of the passage.
And this is at least one correct question per completely incomprehensible passage
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GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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Updated on: 27 Jul 2017, 08:05
1
Time taken 7:35 min. What shld be the expected timing for this Q?
Latest timing 11/07: 5:50 mins.
1. The passage is primarily concerned with
E. describing a line of reasoning put forth by a researcher and addressing a contention concerning that line of reasoning
" astronomer Bohdan Paczynski proposed a way of determining whether the enormous dark halo constituting the outermost part of the Milky Way galaxy is composed of MACHO's
blah blah
Because many individual stars are of intrinsically variable brightness, some astronomers have contended that
blah
blah
However, whereas the different colors of light emitted by an intrinsically variable
"

2. According to the passage, Paczynski's theory presumes that if MACHO's constituted the Milky Way's dark halo, occasionally a MACHO would
B. affect the light rays of a star in the Large Magellanic Cloud with the result that the star would seem for a time to brighten
>>Got this by elimination. Also the language seems to match the para. What I didn't understand is the meaning of "the star would seem for a time to brighten".

3. It can be inferred from the passage that which of the following would constitute the strongest evidence of the microlensing of a star in the Large Magellanic Cloud?
D. The red light, yellow light, and blue light of such a star are observed to be magnified temporarily by the same factor.
>>if a MACHO magnifies a star's red light tenfold, it will do the same to the star's blue light and yellow light.

Originally posted by JarvisR on 12 Aug 2014, 08:41.
Last edited by hazelnut on 27 Jul 2017, 08:05, edited 3 times in total.
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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12 Aug 2014, 09:53
JarvisR wrote:
Time taken 7:35 min. What shld be the expected timing for this Q?

I believe between 5-7min is sufficient for this short RC.
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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12 Aug 2014, 19:39
2
for many short passages in og, gmatprep, the first question about the main idea is hard while the second or third question about a detail in the passage is easy. this passage is an example of this point.

for 2 and 3, the answer is B and D clearly.

for the first, which I feel hard, the answer is C.
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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14 Aug 2014, 23:56
I took 7min++ approx.
E B D (all correct)

OAs are also updated.

Passage was overall easy but it has so many modifiers that affected my thread often.
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Piyush K
-----------------------
Our greatest weakness lies in giving up. The most certain way to succeed is to try just one more time. ― Thomas A. Edison
Don't forget to press--> Kudos
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Tip: Before exam a week earlier don't forget to exhaust all gmatprep problems specially for "sentence correction".

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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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15 Aug 2014, 02:37
PiyushK wrote:
I took 7min++ approx.
E B D (all correct)

OAs are also updated.

Passage was overall easy but it has so many modifiers that affected my thread often.

hi, could you please explain me why B and not D, for Q2

thanks!
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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15 Aug 2014, 22:21
1
1
Below is my reasoning to cancel D.
D)temporarily increase the apparent brightness of a star in the Large Magellanic Cloud by increasing the gravity of the star.
"The gravity of a MACHO that had so drifted, astronomers agree, would cause the star's light rays, which would otherwise diverge, to bend together so that, as observed from Earth, the star would temporarily appear to brighten, a process known as microlensing."

As per the argument, MACHO doesn't increase the gravity to achieve mentioned effect. It's the "drifted gravity " that does it.

Regards.
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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25 Aug 2014, 11:57
1

1.E
2.B
3.D

Time taken - 5mins 45 secs - spent wat too much time with Q1
I am struggling with Primary purpose questions. Would appreciate if someone can share his method. Thnx
Great post once again.
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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01 Oct 2014, 21:43
got the 1st Q wrong.. can anybody please explain this Qstn and similar types
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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02 Feb 2015, 08:38
All correct.

Time : 8 min 20 sec.

First question consumed a lot.

Accuracy is improving ... but only small variations in time..

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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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02 Mar 2015, 11:17
1
Thanks a lot . I support your strategy in fully comprehending the passage first then answering the questions. Sometimes if it is a scientific passage I prefer not to spend so much time understanding the passage fully but just to get a general understanding of what every paragraph speaks about.

quote="deepakpatter"]
saraafifiahmed wrote:
Hi, How long should a RC passage on the actual exam take ? Approximately . Thanks

Well that depends on the length of the passage
Normally for a long passage you should take max to max 5 mins reading so you get the data in your mind. After this the questions are piece of cake.
This is my strategy. Some people just vertical scan the passage in less than minute but i don't prefer that. My strategy works best for me.
Try if it helps.
Once you grasp the content believe me you'll find the answers to the questions so easily within seconds.
KEEP IN MIND..! Avoid reading again and again is the key to rc's. Take time but do it once.
Best if luck..!![/quote]
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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03 Mar 2015, 00:32
deepakpatter wrote:
got the 1st Q wrong.. can anybody please explain this Qstn and similar types

I think you mite b confused b/w C & E.
Isn't it..?

Same was with me.

1. The passage is primarily concerned with
A. outlining reasons why a particular theory is no longer credited by some astronomers
B. presenting data collected by a researcher in response to some astronomers' criticism of a particular line of reasoning
C. explaining why a researcher proposed a particular theory and illustrating how influential that theory has been
D. showing how a researcher's theory has been used to settle a dispute between the researcher and some astronomers
E. describing a line of reasoning put forth by a researcher and addressing a contention concerning that line of reasoning

Option C says WHY researcher proposed the theory... >> The passage no where states this, in fact just says he proposed.
Why he proposed..? We are not bothered..!!

It helped . (y)
thnx a lot
My speed. Is slow with. Rc's
Suggest me something. And am getting 050 percent. Of the answer s wrong
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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04 Mar 2015, 02:39
1
D B E Took me 05:30. Nice passage.
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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22 Mar 2015, 00:40
5 mins 16 secs.all correct.
easy to read passage with easy questions , the inference question that i always suppose to be most hard was also easy .
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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21 Aug 2015, 23:18
Time Taken:
6:51 minutes
1- B. I was confused between B and E
2- B
3- D
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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27 Sep 2015, 02:49
Harley1980 wrote:
I watch "thursdays with Ron" and Ron says about interesting way of solving main idea questions in highly technic RC passages. He recommend to omit all text except key words that change flow of the passage.

Here is my try to do that on this passage:

1) Bohdan Paczynski proposed a way of determining .... [some new theory]
2) Paczynski reasoned that .... [support of theory]
3) Because ... some astronomers have contended that .... [because of something this theory was argue by others astronomers]
4) However .... [author of passage doesn't agree with astronomers]
5) Thus .... [theory is good because of previous word "however"]
6) Moreover .... [and here is one more reason why theory is good]

So we see that first two parts is about new theory, then some arguing and last half of passage support theory.

The passage is primarily concerned with
A. outlining reasons why a particular theory is no longer credited by some astronomers
this answer miss parts 4-6. Incorrect

B. presenting data collected by a researcher in response to some astronomers' criticism of a particular line of reasoning
theory was created before critisms

C. explaining why a researcher proposed a particular theory and illustrating how influential that theory has been
We have only fact of theory and not reasons why it was created. Incorrect

D. showing how a researcher's theory has been used to settle a dispute between the researcher and some astronomers
theory procreate a critism so it can't be used for settling of this dispute. Incorrect

E. describing a line of reasoning put forth by a researcher [1-2 parts]
and addressing a contention concerning that line of reasoning [3-6 parts]

Correct

So with such technic we can solve main idea question even if completely didn't understand topic of the passage.
And this is at least one correct question per completely incomprehensible passage

Very well explained Harley1980 I appreciate your effort

I got 3 on 3 in 6.24 mins

This is the second time that I am solving this RC.
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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29 Sep 2015, 05:15
1E,2B,3D All correct
Time Taken =3 minutes.
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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10 Oct 2015, 18:29
Finished in 10 min.
I got Q2 incorrect. Please, suggest me how to improve on RC. I am really struggling with my speed and accuracy. Big day is just over 2 week from now! My target is 550. Please, help.
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Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn  [#permalink]

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01 Aug 2016, 12:13
6:30
all correct
moderate difficult passage
Re: GMATPREP ChallengeQ -In the 1980's, astronomer Bohdan Paczyn &nbs [#permalink] 01 Aug 2016, 12:13

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