Joined: 19 Jul 2007
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Does anyone know the answer? [
19 Jul 2007, 14:08
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Hi there guys,
This is a tough GMAT question, any hep will be appreciatble
Each employee on a certain task is either a manager or a director. What percent of the employees on the task force are directors?
1. The average (arithmetic mean) salary of the managers on the task force is 5000 less then the average of all employees on the task force
2. The average (arithmetic mean) salary of the directors on the task force is 15000 greater then the average of all employees on the task force
1. Statement 1 is sufficient
2. Statement 2 is sufficient
3. Both statements are sufficient , but neither alone
4. Each statement is sufficient
5. Statements 1 and 2 are not sufficient
Joined: 06 Mar 2006
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The answer to the question is C.
Let's pick numbers. Let's assume manager's avg salary is 10000
(1) This statement tells you that the avg salary of all employee is 15000 according to the number we picked. This statement alone is not sufficient.
(2) Statement 2 is not sufficient for the same reason.
But when you combine the two statement together you can solve for this.
manager's avg salary will be 10000
all employee avg salary will be 15000
director avg salary will be 30000
use knowledge of weighted average
M/(M+D)*(10000) + D/(M+D)*(30000)=15000
D/(M+D)=1/4 or 25% of total.
Joined: 06 Apr 2007
[, given: 0] 0
Let M be the # of managers, D be the # of Directors, and X be the average employee salary
statement 1. M(X-5000) = total salary for managers
statement 2. D(X+15000) = total salary for directors
M(x-5000) + D(X+15000) = (M+D)X
MX-5000M + DX + 15000D = MX + DX
15000D = 5000M
3D = 1M