Venn diagram??

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Venn diagram??

by vardhans83 » Sat Mar 05, 2011 10:26 am
Hi, I have a question that was in some personal material someone gave to me. i have tough time solving these type of questions. Could someone please explain what is the best way to solve it? Thanks

There are 3 kinds of sports: A, B and C. The student learning sport B also learning Sport A. There are 9 students learning sport A and C, 3 learning all the sports, 16 learning just sport A. How many students learn atleast two sports?
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by Night reader » Sat Mar 05, 2011 1:26 pm
i think the answer to this problem is simple - you don't need Venn-diagram... it's asking at least two sports, so count two sports A&C 9 students, three sports A-B-C 3 students, total should make 12 students.

BUT just in case I am attaching pic with Venn-diagram for some else to visualize better :)
vardhans83 wrote:Hi, I have a question that was in some personal material someone gave to me. i have tough time solving these type of questions. Could someone please explain what is the best way to solve it? Thanks
...
Attachments
dr03.JPG
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by vardhans83 » Sat Mar 05, 2011 3:27 pm
I do not understand. It says person who is is playing B also plays A...we dont need to take that in to account?

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by Night reader » Sat Mar 05, 2011 3:30 pm
i took that as a distracting note :( that person who is playing B also plays A does not mean that person who plays A also plays B... We don't know how many students play B, - so I figured only ABC+AC
vardhans83 wrote:I do not understand. It says person who is is playing B also plays A...we dont need to take that in to account?
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by rohu27 » Sat Mar 05, 2011 6:39 pm
infact as evry person who plays B also plays A, if a person plays both B and C he wud automatically play A. tht means all the 3.
so we do need to find only AC+ABC.
Night reader wrote:i took that as a distracting note :( that person who is playing B also plays A does not mean that person who plays A also plays B... We don't know how many students play B, - so I figured only ABC+AC
vardhans83 wrote:I do not understand. It says person who is is playing B also plays A...we dont need to take that in to account?

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by Night reader » Sat Mar 05, 2011 6:47 pm
yes but 9 students don't play game C - they play B and A, besides we know that 3 students play games C and A from knowing about 3 students playing all three games (A-B-C). BUT to avoid over-counting we count only 3 students who play A and C and these 3 already play A and B PLUS there are 9 more students who play ONLY A and B. Total makes 12 students// agree?
rohu27 wrote:infact as evry person who plays B also plays A, if a person plays both B and C he wud automatically play A. tht means all the 3.
so we do need to find only AC+ABC.
Night reader wrote:i took that as a distracting note :( that person who is playing B also plays A does not mean that person who plays A also plays B... We don't know how many students play B, - so I figured only ABC+AC
vardhans83 wrote:I do not understand. It says person who is is playing B also plays A...we dont need to take that in to account?
My knowledge frontiers came to evolve the GMATPill's methods - the credited study means to boost the Verbal competence. I really like their videos, especially for RC, CR and SC. You do check their study methods at https://www.gmatpill.com