GMAT PREP - Percentages

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GMAT PREP - Percentages

by Blast » Fri Nov 28, 2008 11:46 am
I don't fully understand why statement 2 is sufficient in this case. Any help is appreciated. Thanks!
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by cramya » Fri Nov 28, 2008 12:26 pm
Stmt I

Clearly insufficient

No info about 1980 or 1990

Stmt II

Let the pop in 1970 be x

1980 = 1.2x
1990 = 1.3x

Percent Increase(1980-1990) = New(1990)-Old(1980)/Old(1980) *100
= 1.3x-1.2x / 1.2x *100
= .1x/1.2x*100
= 10/1.2 = 8.3%

No caculation needed once u know stm II is SUFF but i have included it for your FYI

B)

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by vittalgmat » Fri Nov 28, 2008 1:08 pm
Thanks cramya.
I tripped on this one!!!!!! : (