GPREP CityK DS

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GPREP CityK DS

by aj5105 » Thu Jan 15, 2009 11:41 pm
What was the % increase in the population of City K from 1980 to 1990?

1) In 1970 the population of City K was 160,000.
2) In 1980 the population of City K was 20% greater than it was in 1970, and in 1990 the population of City K was 30% greater than it was in 1970.

Statement 1) Not Sufficient

Statement 2) [(P90 - P80)/P80] * 100

[(P70+0.3P70)-(P70+0.2P70]) / 1.2P70 * 100

As i simplify the above I get i get 8.5 %

Is my approach right?
Source: — Data Sufficiency |

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Re: GPREP CityK DS

by logitech » Fri Jan 16, 2009 12:00 am
Your approach is complicated and prone to calculation errors

1) In 1970 the population of City K was 160,000.
Insif

2) In 1980 the population of City K was 20% greater than it was in 1970, and in 1990 the population of City K was 30% greater than it was in 1970.

70 = 100
80 = 120
90 = 130

So yes we can find the % increase 120-->130
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by rkh13 » Fri Jan 16, 2009 12:07 am
so the answer is C right?

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by logitech » Fri Jan 16, 2009 12:09 am
rkh13 wrote:so the answer is C right?
Why do you need the first statement ?
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by aj5105 » Fri Jan 16, 2009 12:41 am
yeah - much simpler.