Events & Promotions
|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Sep 1507:00 PM EDT
-09:00 PM EST
Elite scores are possible when you enroll in a powerful GMAT course, taught live online + 6 months access to TTP OnDemand video courses included! Class starts Tues/Thurs Sept. 15, 2026 - Nov. 15, 2027, 7:00pm-9:00pm EST
Sep 2107:00 PM EDT
-10:00 PM EDT
Boost your GMAT score in less than one month in a live online class + 6 months access to TTP OnDemand video courses included! Class starts Mon, Tues, Wed, Thur, Fri Sept. 21, 2026 - Oct. 9, 2027, 7:00pm-10:00pm EST
12 Oct 2004, 20:37
Kudos
Bookmarks
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
55%
(hard)
Question Stats:
66% (02:20) correct
34%
(02:34)
wrong
based on 631
sessions
History
Date
Time
Result
Not Attempted Yet
Each of three charities in Novel Grove Estates has 8 persons serving on its board of directors. If exactly 4 persons serve on 3 boards each and each pair of charities has 5 persons in common on their boards of directors, then how many distinct persons serve on one or more boards of directors?
A. 8
B. 13
C. 16
D. 24
E. 27
A. 8
B. 13
C. 16
D. 24
E. 27
Each group has 8 = 8+8+8 = 24 max
4 people are in 2 groups, subtract 4 people twice as they are counted twice
Each pair of groups has 5 in common, so in addition to the 4 people subtract 1 from each group
Ans: 8+8+8-(2(4)) - 3 = 13
4 people are in 2 groups, subtract 4 people twice as they are counted twice
Each pair of groups has 5 in common, so in addition to the 4 people subtract 1 from each group
Ans: 8+8+8-(2(4)) - 3 = 13
31 Jan 2011, 21:26
Kudos
Bookmarks
m990540
You can use the formula for 3 sets:
n(AUBUC) = n(A) + n(B) + n (C) - n(A and B) - n(B and C) - n(C and A) + n(A and B and C)
n(AUBUC) = 8 + 8 + 8 - 5 - 5 -5 + 4 = 13
Though, why would you not try using the Venn diagram for 3 overlapping sets. This question is relatively straight forward so the formula is no problem, but with the Venn diagram, it doesn't matter how much you twist the question, the answer is still apparent....
I am attaching it in case you would like to give it a look...
Attachment:
Ques2.jpg [ 10.5 KiB | Viewed 18515 times ]
14 May 2011, 23:43
Kudos
Bookmarks
Let Communities be C1, C2 and C3. It given that exactly 4 members serve on 3 boards each. Hence 4 member in all three communities.
Also each pair of charity has 5 persons in common. hence 1 member between C1 and C2 Only.
Total = 2+2+2+1+1+1+4=13.
OA B.
Also each pair of charity has 5 persons in common. hence 1 member between C1 and C2 Only.
Total = 2+2+2+1+1+1+4=13.
OA B.
Attachments
venn diagram.JPG [ 22.61 KiB | Viewed 20063 times ]
