a data from gmat club

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a data from gmat club

by diebeatsthegmat » Fri Jun 17, 2011 8:31 am
In a school, 70% teach Science, 64% Economics, and 60% teach English. Atleast 40% of those who teach English also teach either science or Economics. How many of the teachers teach atleast 2 or 3 of the subject.
1. 50% of the teachers teach all the 3 subjects.
2. atleast 20% of the teachers who teach Science also teach Economics.

my answer for this kind of question is E in 10 seconds because it asked " how many of the teachers" since it doesnt give the total number of the teachers in the school... we dont know how many teachers exactly to answer
but if it asked about percent " how many percent" it should be D, right?
Source: — Data Sufficiency |

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by amit2k9 » Fri Jun 17, 2011 8:52 pm
70+64+60 - SEc- 40 - 2S_EC_EN = 100

a provides for SEc. hence sufficient.

b provides for S_Ec_En hence sufficient.

D it is.
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by Anurag@Gurome » Fri Jun 17, 2011 9:50 pm
diebeatsthegmat wrote:In a school, 70% teach Science, 64% Economics, and 60% teach English. Atleast 40% of those who teach English also teach either science or Economics. How many of the teachers teach atleast 2 or 3 of the subject.
1. 50% of the teachers teach all the 3 subjects.
2. atleast 20% of the teachers who teach Science also teach Economics.

my answer for this kind of question is E in 10 seconds because it asked " how many of the teachers" since it doesnt give the total number of the teachers in the school... we dont know how many teachers exactly to answer
but if it asked about percent " how many percent" it should be D, right?
Yes. You are right. Ideally, the question should ask "What percentage of teachers teach at least 2 or 3 of the subjects".
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by Sanjay2706 » Sat Jun 18, 2011 5:41 am
IMO E.
What's the OA?