voodoochild wrote:

In a certain company, employees receive their salary on a monthly basis and are paid on either 10th or 20th of each month. If 65 percent of all managers are paid on 10th of each month and 79% of employees who are paid on 20th of each month are not managers, what percent of the company employees are managers?

12%

15%

20%

21%

the answer cannot be derived from the data provided

Here's what I did:

on the 20th, 0.35M = .21 E (because 35% of managers will get paid on the 20th; 21% of employees are managers)

therefore, M/E = 60%

Thoughts?

21% of those paid on the 20th are managers, it doesn't mean that 21% of all employees are managers.

There are employees paid on the 10th, those paid on the 20th are not all the non-manager employees.

Also, managers can be divided into two groups: those paid on the 10th, and those paid on the 20th.

And you don't know anything about the employees (non-managers) paid on the 10th.

Try to use the 2 X 2 table method and you will see that you cannot fill it out. Or the Venn diagram.

Answer: E

_________________

PhD in Applied Mathematics

Love GMAT Quant questions and running.