Mary,Jim & kate

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Mary,Jim & kate

by prachich1987 » Sat Jan 01, 2011 11:29 pm
The difference between Mary and Jim's salary was twice the difference between Mary and Kate's. If Mary had the highest salary, what was the average of the three?

a. Jim's salary was $30,000
b. Kate's was $40,000
Source: — Data Sufficiency |

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by Anurag@Gurome » Sun Jan 02, 2011 12:15 am
prachich1987 wrote:The difference between Mary and Jim's salary was twice the difference between Mary and Kate's. If Mary had the highest salary, what was the average of the three?

a. Jim's salary was $30,000
b. Kate's was $40,000
Say, Jim's salary = $a, Kate's salary = $b and Mary's salary = $c
Where c is greater than a and b.
Now, (c - a) = 2(c - b)
=> (c - a) = (2c - 2b)
=> (a + c) = 2b

We have to find (a + b + c)/3 = (2b + b)/3 = 3b/3 = b

Statement 1: a = 30,000 => Not sufficient

Statement 2: b = 40,000 => Sufficient

The correct answer is B.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
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