three set problem

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three set problem

by myself2014 » Tue Mar 25, 2014 11:29 pm
i tried working this and am getting negative answers and i doubt my answers because it not possible to get negative number of people. PLEASE HELP ME
QUESTION
A college doctor found out that 40 students have had food poisoning. He found out the following after interviewing them.
25, 27 and 30 took rice, beans and plantain respectively.
28 took rice or plantain but not beans
13 took rice and plantain
10 took rice but did not take beans and plantain
7 took beans and plantain but not rice
determine the number of students who
a. took none of the meal
b. took all the three meal
c. took only one meal
d. took more than one meal

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by [email protected] » Wed Mar 26, 2014 12:30 am
Hi myself2014,

This is clearly not in the proper format to be a GMAT question. While this type of 3-group overlapping sets question is rare on Test Day it WILL NOT allow for people who aren't in any of the groups (in this case, people who "took none of the meals").

That having been said, I think that there are some typos/incorrect information in the question. What is the source?

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by Jim@StratusPrep » Tue Apr 01, 2014 8:11 am
Yeah, I would ignore this question. It is pretty bad all around.
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