Venn Diagram

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Venn Diagram

by chdn20 » Sun May 16, 2010 5:30 am
Of the 84 parents who attended a meeting at a school, 35 volunteered to supervise children during the school picnic and 11 volunteered both to supervise children during the picnic and to bring refreshments to the picnic. If the number of parents who volunteered to bring refreshments was 1.5 times the number of parents who neither volunteered to supervise children during the picnic nor volunteered to bring refreshments, how many of the parents volunteered to bring refreshments?

A) 25
B) 36
C) 38
D) 42
E) 45

Any sight would be great. I have been trying to solve the problem using the group 1+group 2+ neither + both, but its not working.

Can you solve using a variation of this:

24+11+1.5x+x=84?

Thanks,

Chris

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by clock60 » Sun May 16, 2010 5:49 am
chdn20 wrote:Of the 84 parents who attended a meeting at a school, 35 volunteered to supervise children during the school picnic and 11 volunteered both to supervise children during the picnic and to bring refreshments to the picnic. If the number of parents who volunteered to bring refreshments was 1.5 times the number of parents who neither volunteered to supervise children during the picnic nor volunteered to bring refreshments, how many of the parents volunteered to bring refreshments?

A) 25
B) 36
C) 38
D) 42
E) 45

Any sight would be great. I have been trying to solve the problem using the group 1+group 2+ neither + both, but its not working.

Can you solve using a variation of this:

24+11+1.5x+x=84?

Thanks,

Chris
many ways are possible one of them is double matrix

___________ supervise ____ not supervise______ total
_bring refresh _11___________ ________________1.5 x
not bring refr__24___________ x______________ (24 +x)
__ total_____ 35___________49______________84

1.5x+(24+x)=84
x=24
24*1,5=36
so my answer B ( some figures in the table are useless don`t pay attention)

let me know OA?

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by chdn20 » Sun May 16, 2010 5:54 am
Thanks for the help. Why would you not at the 11 people?

Thanks

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by clock60 » Sun May 16, 2010 7:48 am
chdn20 wrote:Thanks for the help. Why would you not at the 11 people?

Thanks
the problem asks
how many of the parents volunteered to bring refreshments?
11 includes both who bring refreshments and supervise, but we need those who supervise and bring +not supervise but bring

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by harshavardhanc » Sun May 16, 2010 7:50 am
chdn20 wrote: Any sight would be great. I have been trying to solve the problem using the group 1+group 2+ neither + both, but its not working.

Can you solve using a variation of this:

24+11+1.5x+x=84?

Thanks,

Chris
you were very close!

the equation will become : 24 + x + 2/3 x = 84 , where x is the number of people who bring refreshments.

you'll get the answer as 36.
Regards,
Harsha

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by indiantiger » Sun May 16, 2010 5:06 pm
I agree, you were very close:

I used this formula
Group1+ Group2 -Both + Neither = Total

35+3/2*N-11+N = 84

this becomes

84-24 = 5/2*N
60*2/5 = N
N = 24

Parents bringing refreshments = 3/2*24 = 36(B)

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by frank1 » Sun May 16, 2010 7:08 pm
i think one motive of asking question like this is suck up the time.....
one has to collect lots of info here (and if not is hasty s/he will easily mis-collect the info) and at wrost case they have answer matching wrong information collection
i used this
84-x=35+1.5x-11

i.e x=24
1.5x=36