BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Percentage Critical reasoning from KAPLAN: MEDIUM HARD

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 171
Joined: Sat May 03, 2008 3:51 pm
Thanked: 8 times

Percentage Critical reasoning from KAPLAN: MEDIUM HARD

by wawatan » Mon Jun 02, 2008 4:51 pm
In 1980, 13 percent of the Arbican population
moved from urban areas to suburban areas. This percentage
steadily declined, until, in 1990, it reached 3%.

If the statements above are all true, all of the following
statements concerning Arbicans between 1980 and 1990 could also
be true EXCEPT:

A. The number of Arbicans moving from
suburban areas to urban areas also decreased

B. The Arbican population increased, and so did the number
of Arbicans moving from urban to suburban areas

C. the arbican population decreased and so did the number of Arbicans
moving from urban to suburban areas.

d. The arbican population decreased, and the number of Arbicans moving
from urban to suburban areas remained the same.

E. The Arbican population increased, and the number of Arbicans moving from
urban to suburban areas remained the same.

Please explain why A is wrong.

Will post OA Later.
Top
Source: — Critical Reasoning |
Master | Next Rank: 500 Posts
Posts: 167
Joined: Tue Apr 22, 2008 12:48 am
Thanked: 15 times

by durgesh79 » Mon Jun 02, 2008 11:02 pm
First, the question talks about people moving from Urban to Suburban.

Option A talks about number fo people moving from Suburban to Urban.

Lets look at D.

If the total Population decreased and the number of people remained the same the % should have increased. So D can not be True.
Top
Master | Next Rank: 500 Posts
Posts: 171
Joined: Sat May 03, 2008 3:51 pm
Thanked: 8 times

by wawatan » Tue Jun 03, 2008 3:07 am
i don't understand how A can be true. There's nothing in the passage that says the population is moving from suburban areas to urban areas. This is a faulty assumption. Anyone else agrees?
Top
Junior | Next Rank: 30 Posts
Posts: 23
Joined: Wed Jun 06, 2007 9:35 am

by mttorii » Tue Jun 03, 2008 11:04 am
D is the answer because it could not be true.
The passage does not give any information about the number of Arbicans that move from suburban areas to urban areas, so we can not confirm wether alternative A is true or not. Again, based on the passage, you can not say that A is 100% wrong.
Top
Senior | Next Rank: 100 Posts
Posts: 87
Joined: Mon May 07, 2012 7:57 am
Thanked: 1 times

by mparakala » Tue Jan 29, 2013 7:46 pm
U----> S (movement of Arbican population)
1980: 13%
1990: 3%

number of people moving / total number of people

this percentage has to decrease. in option D, if the number of people (numerator) is constant and the total no. of people is decreasing (denominator), then the percentage will increase- this is contrary to the information in the stimulus. Hence, this is incorrect.

Ans: D
Top
Senior | Next Rank: 100 Posts
Posts: 78
Joined: Wed Jan 09, 2013 5:03 am
Thanked: 9 times
Followed by:4 members
GMAT Score:700

by shenoydevika » Wed Jan 30, 2013 9:33 pm
Answer should be D.

If the population of Arbicans decreased but the number of Arbicans moving to the suburban areas remained the same, the percentage should have increased. D is the only one that could not be true.

A is out of scope and irrelevant. The number of Arbicans moving from the suburban areas to the urban areas should not affect the percentage of Arbicans moving from urban to suburban areas (unless we are specifically told it does)


OA please
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 111
Joined: Tue Jan 31, 2012 1:06 pm
Thanked: 15 times
Followed by:8 members

by charu_mahajan » Thu Jan 31, 2013 10:30 am
+1 for D.
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 113
Joined: Sun Aug 22, 2010 12:37 am
Thanked: 16 times
Followed by:4 members

by challenger63 » Thu Jan 31, 2013 8:21 pm
deleted.
Last edited by challenger63 on Thu Jan 31, 2013 8:24 pm, edited 2 times in total.
If you find my post useful, please don't hesitate to click thanks button.


I am not an expert, so I can make mistakes. If you see a mistake, please notify me.
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 113
Joined: Sun Aug 22, 2010 12:37 am
Thanked: 16 times
Followed by:4 members

by challenger63 » Thu Jan 31, 2013 8:22 pm
The answer is definitely D.
The key to this question is the modal verb "COULD".
In 1980, 13 percent of the Arbican population moved from urban areas to suburban areas. This percentage steadily declined, until, in 1990, it reached 3%.

If the statements above are all true, all of the following
statements concerning Arbicans between 1980 and 1990 could also
be true EXCEPT:
A. The number of Arbicans moving from suburban areas to urban areas also decreased
>> It is definitely possible. For example, in 1980, we have 100 suburban residents, from which 13 moved to suburbs. It is possible that 2 people either return or 2 former suburb's residents moved to urban areas. The migration flow is definitely COULD be in two directions.
B. The Arbican population increased, and so did the number of Arbicans moving from urban to suburban areas
>> Why not? Imagine, we have 100 residents in 1980 => 13 immigrant. Then, the number of residents grew dramatically but the number of immigrant did only slightly.

Thus, we COULD have 1980,100,13 => 1990, 10000, 300.
C. the arbican population decreased and so did the number of Arbicans moving from urban to suburban areas.
>> Also possible. We COULD have 1980, 1000, 130 => 1990, 100, 3
d. The arbican population decreased, and the number of Arbicans moving
from urban to suburban areas remained the same.
>> NOT POSSIBLE. If we have 1980, 1000, 13 => 1990, 100, 3% CAN'T BE EQUAL TO 13!
E. The Arbican population increased, and the number of Arbicans moving from
urban to suburban areas remained the same.
>> why not? increase in population COULD decrease the ratio number of immigrants to the whole population.
If you find my post useful, please don't hesitate to click thanks button.


I am not an expert, so I can make mistakes. If you see a mistake, please notify me.
Top
Post new topic Post Reply
• Page 1 of 1