BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Venn Diagram

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Newbie | Next Rank: 10 Posts
Posts: 7
Joined: Sun Dec 27, 2009 6:02 am

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
Top
Source: — Problem Solving |
Legendary Member
Posts: 759
Joined: Mon Apr 26, 2010 10:15 am
Thanked: 85 times
Followed by:3 members

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?
Top
Newbie | Next Rank: 10 Posts
Posts: 7
Joined: Sun Dec 27, 2009 6:02 am

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

Thanks
Top
Legendary Member
Posts: 759
Joined: Mon Apr 26, 2010 10:15 am
Thanked: 85 times
Followed by:3 members

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
Top
User avatar
Legendary Member
Posts: 526
Joined: Sat Feb 21, 2009 11:47 pm
Location: India
Thanked: 68 times
GMAT Score:680

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
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 362
Joined: Fri Oct 02, 2009 4:18 am
Thanked: 26 times
Followed by:1 members

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)
Top
Legendary Member
Posts: 537
Joined: Fri Jan 22, 2010 10:06 pm
Thanked: 14 times
Followed by:1 members

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
Top
Post new topic Post Reply
• Page 1 of 1