Each person who attended a company meeting was either a stockholder in the company, an employee of the company, or both. If 62 percent of those who attended the meeting were stockholders and 47 percent were employees, what percent were stockholders who were not employees?
(A) 34%
(B) 38%
(C) 45%
(D) 53%
(E) 62%
OAD
Please explain by double matrix.
Thanks
what percent were stockholders who were not employees?
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Let's plug in what we know. If 62% of the people at the meeting were stockholders, then 38% were not. If 47% of the people at the meeting were employees then 53% were not. Note, also, that everyone is an employee or stockholder or both, so the "not stockholder"/"not employee" cell will be 0. Now we've got this:
We're looking for the stockholders/not employees cell. It's in red here:
Matrix problem!rsarashi wrote:Each person who attended a company meeting was either a stockholder in the company, an employee of the company, or both. If 62 percent of those who attended the meeting were stockholders and 47 percent were employees, what percent were stockholders who were not employees?
(A) 34%
(B) 38%
(C) 45%
(D) 53%
(E) 62%
OAD
Please explain by double matrix.
Thanks
Let's plug in what we know. If 62% of the people at the meeting were stockholders, then 38% were not. If 47% of the people at the meeting were employees then 53% were not. Note, also, that everyone is an employee or stockholder or both, so the "not stockholder"/"not employee" cell will be 0. Now we've got this:
We're looking for the stockholders/not employees cell. It's in red here:
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Hi rsarashi,
This is essentially an Overlapping Sets question that does not have a "neither" group. As such, it can be solved in a couple of different ways. Here's how you can use standard Overlapping Sets formula to get to the correct answer:
Total = (Group 1) + (Group 2) - (Both) + (Neither)
Group 1 = % that are stockholders
Group 2 = % that are employees
100% = 62% + 47% - (Both) + 0%
100% = 109% - (Both)
Both = 9%
So 9% of the total attendees are BOTH stockholders AND employees. We're asked for the percent who were stockholders but NOT employees:
62% - 9% = 53%
Final Answer: D
GMAT assassins aren't born, they're made,
Rich
This is essentially an Overlapping Sets question that does not have a "neither" group. As such, it can be solved in a couple of different ways. Here's how you can use standard Overlapping Sets formula to get to the correct answer:
Total = (Group 1) + (Group 2) - (Both) + (Neither)
Group 1 = % that are stockholders
Group 2 = % that are employees
100% = 62% + 47% - (Both) + 0%
100% = 109% - (Both)
Both = 9%
So 9% of the total attendees are BOTH stockholders AND employees. We're asked for the percent who were stockholders but NOT employees:
62% - 9% = 53%
Final Answer: D
GMAT assassins aren't born, they're made,
Rich
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Let's use the Double Matrix Method.rsarashi wrote:Each person who attended a company meeting was either a stockholder in the company, an employee of the company, or both. If 62 percent of those who attended the meeting were stockholders and 47 percent were employees, what percent were stockholders who were not employees?
(A) 34%
(B) 38%
(C) 45%
(D) 53%
(E) 62%
This technique can be used for most questions featuring a population in which each member has two characteristics associated with it (aka overlapping sets questions).
Here, we have a population of attendees, and the two characteristics are:
- stockholder or not a stockholder
- employee or not an employee
Since we're not told the total number of attendees, and since we're trying to find a PERCENTAGE, let's assign a nice value to the total number of attendees
Let's say there are 100 attendees
Finally, since we're looking for the percentage of attendees who were stockholders but NOT employees, let's place a red star in that box to remind us of what we're trying to determine.
62 percent of those who attended the meeting were stockholders
This also means that the other 38 percent are NOT stockholders
47 percent were employees
This also means that the other 53 percent are NOT employees
At this point, we appear to have no more information to add to our diagram.
However, we also know that each person who attended a company meeting was either a stockholder in the company, an employee of the company, or both
This means that there were ZERO people who were neither a stockholder nor an employee.
So, we can add this to our diagram.
Since the two boxes in the right-hand column must add to 53, we know that the top right box must have 53 people in it...
What percent were stockholders who were not employees?
Out of 100 attendees, 53 people were stockholders but not employees
In other words, 53% of the people were stockholders but not employees
Answer: D
This question type is VERY COMMON on the GMAT, so be sure to master the technique.
To learn more about the Double Matrix Method, watch this video: https://www.gmatprepnow.com/module/gmat- ... ems?id=919
Once you're familiar with this technique, you can attempt these additional practice questions:
Easy Problem Solving questions
- https://www.beatthegmat.com/finance-maj ... 67425.html
Medium Problem Solving questions
- https://www.gmatprepnow.com/module/gmat- ... /video/920
- https://www.beatthegmat.com/posted-spee ... 72374.html
- https://www.beatthegmat.com/motel-t271938.html
- https://www.beatthegmat.com/of-the-appl ... 70255.html
- https://www.beatthegmat.com/opening-nig ... 64869.html
- https://www.beatthegmat.com/at-least-10 ... 74669.html
- https://www.beatthegmat.com/prblem-solving-t279424.html
Difficult Problem Solving questions
- https://www.gmatprepnow.com/module/gmat- ... /video/946
- https://www.beatthegmat.com/ratio-problem-t268339.html
- https://www.beatthegmat.com/overlapping ... 65223.html
- https://www.beatthegmat.com/fractions-t264254.html
- https://www.beatthegmat.com/overlapping ... 64092.html
- https://www.beatthegmat.com/mba/2011/05 ... question-2
Easy Data Sufficiency questions
- https://www.gmatprepnow.com/module/gmat- ... /video/943
- https://www.beatthegmat.com/for-what-pe ... 70596.html
- https://www.beatthegmat.com/ds-quest-t187706.html
Medium Data Sufficiency questions
- https://www.beatthegmat.com/sets-matrix-ds-t271914.html
- https://www.beatthegmat.com/each-of-peo ... 71375.html
- https://www.beatthegmat.com/a-manufacturer-t270331.html
- https://www.beatthegmat.com/in-costume- ... 69355.html
- https://www.beatthegmat.com/mba/2011/05 ... question-1
Difficult Data Sufficiency questions
- https://youtu.be/dsCeqF9Kbk8
- https://www.beatthegmat.com/double-set- ... 71423.html
- https://youtu.be/dOZ9KM1m5Hs
- https://www.beatthegmat.com/sets-t269449.html
- https://www.beatthegmat.com/mba/2011/05 ... question-3
Cheers,
Brent
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We can use the equation:rsarashi wrote:Each person who attended a company meeting was either a stockholder in the company, an employee of the company, or both. If 62 percent of those who attended the meeting were stockholders and 47 percent were employees, what percent were stockholders who were not employees?
(A) 34%
(B) 38%
(C) 45%
(D) 53%
(E) 62%
Total = Stockholders + Employees - Both + Neither
100 = 62 + 47 - Both + 0
100 = 109 - Both
Both = 9
Thus, the percent of people at the meeting who were stockholders but not employees (i.e., stockholders only) is 62 - 9 = 53 percent.
Answer: D
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