Source: Official Guide for GMAT Review 2016 Data Sufficiency ; #109

2

# In a certain office, 50 percent of

In a certain office, 50 percent of the employees are college graduates and 60 percent of the employees are over 40 years old. If 30 percent of those over 40 have master's degrees, how many of the employees over 40 have master's degrees?

### 2 Explanations

1

ZOE ZHUYAN

Hi tutors,

I picked up E, because I doubt whether there are only two group , master and college, in the certain company.
and the question does not state only two group in the company.

no matter statement #1 or #2 or both #1 and #2, each is insufficient,

have a nice day
>_~

Nov 8, 2016 • Comment

Sam Kinsman

Hi Zoe,

You're right that there could be more groups - there could be people who don't have a college degree, and there could be people who have a Phd.

However, with statement 1, we can still find the how many of the employees over 40 have master's degrees.

Statement 1 tells us that exactly 100 of the employees are college graduates. And we know that 50 percent of the employees are college graduates. So 100 = 50%, so there must be 200 employees in the office. From there, we use the information that's given in the prompt to find out how many of the employees over 40 have master's degrees. The exact method for is explained in the video below! :)