% of employess

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% of employess

by ashforgmat » Thu May 13, 2010 9:47 pm
147) At a company employees are either managers or directors, what percentage of employees are directors?
a. The average salary of managers is $5000 less than average of all employees
b. The average salary of directors is $15000 greater than average salary of all employees.


Please can someone help with the explanation of this question.

Thanks,
Ash.

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by pradeepkaushal9518 » Thu May 13, 2010 9:59 pm
we need to calculate % of employee who r directors for that we need number of total employee and no of directors or no or managers.

1.This doesn't give any information about no of managers or no of employees. hence not sufficient so A and D out

left wid BCE

2. this also doesnt give any information so B is out left with C and E

i dont think combining both will give information so i choose E

what is OA?

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by ashforgmat » Fri May 14, 2010 12:56 am
Answer is C as below :-

Let X be the percentage of directors and 100-X be the percentage of managers.
Let D be the salary of directors and M be the salary of managers
av (directors)= D, Av. (Managers) = M, Av.(all Employees) = [DX + M(100-X)]/100
Statement A. M - [DX + M(100-X)]/100 = 5000 --> (M-D)X = 5000x100...........(i) not sufficient
Statement B. [DX + M(100-X)]/100 - D = 15000 --> (D-M)X/100 + M-D = 15000........(ii) not sufficient

combined: -5000 + M-D =15000 --> M-D = 20000
from X = 5000x100/20000 = 25 % Ans C

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by gmatmachoman » Fri May 14, 2010 5:39 am
ashforgmat wrote:Answer is C as below :-

Let X be the percentage of directors and 100-X be the percentage of managers.
Let D be the salary of directors and M be the salary of managers
av (directors)= D, Av. (Managers) = M, Av.(all Employees) = [DX + M(100-X)]/100
Statement A. M - [DX + M(100-X)]/100 = 5000 --> (M-D)X = 5000x100...........(i) not sufficient
Statement B. [DX + M(100-X)]/100 - D = 15000 --> (D-M)X/100 + M-D = 15000........(ii) not sufficient

combined: -5000 + M-D =15000 --> M-D = 20000
from X = 5000x100/20000 = 25 % Ans C

I dont think this is the right explanation for the above said conditions!! Plz recheck them.

@pradeep....It has to be E