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## Average problem

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phoenix9801 Really wants to Beat The GMAT!
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Average problem Thu May 31, 2012 10:38 am
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• Lap #[LAPCOUNT] ([LAPTIME])
4-
The average (arithmetic mean) of 20, 60, and 100 is 10 more than the average of 40, 80, and which of the following?

A) 110
B) 90
C) 70
D) 50
E) 30

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aneesh.kg GMAT Destroyer!
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Thu May 31, 2012 12:53 pm
phoenix9801 wrote:
4-
The average (arithmetic mean) of 20, 60, and 100 is 10 more than the average of 40, 80, and which of the following?

A) 110
B) 90
C) 70
D) 50
E) 30
Let the unknown number be x. Then

(20 + 60 + 100)/3 = (40 + 80 + x)/3 + 10
60 = 40 + x/3 + 10
x = 30

(E) is correct.

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Aneesh Bangia
GMAT Math Coach
aneesh.bangia@gmail.com

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