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by Mjkourtis » Thu Oct 18, 2012 7:00 pm
A certain city with a population of 132,000 is to be divided into 11 voting districts and no district is to have a population of more than 10% greater than the population of any other district. What is the minimum population that the least populated district could have?
A. 10,700
B. 10,800
C. 10,900
D. 11,000
E. 11,100
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Source: — Problem Solving |

by Anurag@Gurome » Thu Oct 18, 2012 7:01 pm
Mjkourtis wrote:A certain city with a population of 132,000 is to be divided into 11 voting districts and no district is to have a population of more than 10% greater than the population of any other district. What is the minimum population that the least populated district could have?
A. 10,700
B. 10,800
C. 10,900
D. 11,000
E. 11,100
Algebraic Approach:

Let us assume that the minimum possible population = x
Then the maximum population = x + 10% of x = 1.1x
For x to be minimum, only one district should have minimum possible population, while the other 10 districts should have the same population, which is equal to 1.1x
So, x + 1.1*10x = 132000
12x = 132000
x = 11,000

The correct answer is D.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

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by Anurag@Gurome » Thu Oct 18, 2012 7:31 pm
Mjkourtis wrote:A certain city with a population of 132,000 is to be divided into 11 voting districts and no district is to have a population of more than 10% greater than the population of any other district. What is the minimum population that the least populated district could have?
A. 10,700
B. 10,800
C. 10,900
D. 11,000
E. 11,100
We can also solve it like this:

Population of each district = 132000/11 = 12000
Let the least populated district have a population of 10,000.
Then, 10% greater than 10,000 = (0.10 * 10,000) + 10,000 = 1,000 + 10,000 = 11,000
With one district with 10,000 and other districts greater than 10,000, there has to be at least one district greater than 11,000.

Now 10,000 as the least populated district is not possible.
So, 11,000 as the least populated district satisfies the condition.

The correct answer is D.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

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