In a survey of 100 families the no. that read recent issues of a certain monthly magazine were found to be;
September only 18
September but not August 23
September & July 8
september 26
July 48
July & August 8
None of the 3 months 24.
With the help of the set theory find;
(a)How many read the August issue?
(b)How many read 2 consecutive issues?
(c)How many read the July issue if and only if they did not read the August issue?
(d)How many read September & August issues but did not read the July issue?
please atach sum explanation to your working thank you.
Set theory problem.
This topic has expert replies
-
- Newbie | Next Rank: 10 Posts
- Posts: 3
- Joined: Tue Apr 24, 2012 1:11 am
- Birottam Dutta
- Master | Next Rank: 500 Posts
- Posts: 342
- Joined: Wed Jul 08, 2009 8:50 am
- Thanked: 214 times
- Followed by:19 members
- GMAT Score:740
According to the question,
a= 18 (September only 18 )-----(1)
a+b+d+f = 26 (september 26 )-----(2)
g+f+d+e = 48 (July 48 )-----(3)
d+e= 8 (July & August 8)-----(4)
d+f = 8 (September & July 8)-----(5)
a+f = 23 (September but not August 23)-----(6)
a+b+c+d+e+f+g = 76 (None of the 3 months 24)-----(7)
From (1) and (6), f=5---- (8)
From (8) and (5), d=3 --- (9)
From (9) and (4), e=5---- (10)
From (3), (8), (9) and (10), g= 35 --- (11)
From (2), (8), (9) and (1), b = 0
As only c is missing, putting values of all other unknowns in (7), we get c= 10.
Now let us answer the questions:
(a) August = b+c+d+e = 18
(b) Two consecutive issues will be either July August or August September = e + b = 5+ 0 = 5
(c) July minus August = g + f = 35 + 5 = 40
(d) Sept + Aug - July = b = 0.
Hope these are correct!
a= 18 (September only 18 )-----(1)
a+b+d+f = 26 (september 26 )-----(2)
g+f+d+e = 48 (July 48 )-----(3)
d+e= 8 (July & August 8)-----(4)
d+f = 8 (September & July 8)-----(5)
a+f = 23 (September but not August 23)-----(6)
a+b+c+d+e+f+g = 76 (None of the 3 months 24)-----(7)
From (1) and (6), f=5---- (8)
From (8) and (5), d=3 --- (9)
From (9) and (4), e=5---- (10)
From (3), (8), (9) and (10), g= 35 --- (11)
From (2), (8), (9) and (1), b = 0
As only c is missing, putting values of all other unknowns in (7), we get c= 10.
Now let us answer the questions:
(a) August = b+c+d+e = 18
(b) Two consecutive issues will be either July August or August September = e + b = 5+ 0 = 5
(c) July minus August = g + f = 35 + 5 = 40
(d) Sept + Aug - July = b = 0.
Hope these are correct!
- Attachments
-
Folks please check this out
https://www.youtube.com/watch?v=H7p56NzAVKc
https://www.youtube.com/watch?v=H7p56NzAVKc
- Stuart@KaplanGMAT
- GMAT Instructor
- Posts: 3225
- Joined: Tue Jan 08, 2008 2:40 pm
- Location: Toronto
- Thanked: 1710 times
- Followed by:614 members
- GMAT Score:800
Hi,
I'm a bit confused about what this has to do with:
1) data sufficiency; and
2) the GMAT!
Thanks,
Stuart
I'm a bit confused about what this has to do with:
1) data sufficiency; and
2) the GMAT!
Thanks,
Stuart
Vookeh dyzynah wrote:In a survey of 100 families the no. that read recent issues of a certain monthly magazine were found to be;
September only 18
September but not August 23
September & July 8
september 26
July 48
July & August 8
None of the 3 months 24.
With the help of the set theory find;
(a)How many read the August issue?
(b)How many read 2 consecutive issues?
(c)How many read the July issue if and only if they did not read the August issue?
(d)How many read September & August issues but did not read the July issue?
please atach sum explanation to your working thank you.
Stuart Kovinsky | Kaplan GMAT Faculty | Toronto
Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
- ronnie1985
- Legendary Member
- Posts: 626
- Joined: Fri Dec 23, 2011 2:50 am
- Location: Ahmedabad
- Thanked: 31 times
- Followed by:10 members
(a) 18
(b) 5
(c)40
(d) 0
See the attachment for explanation
(b) 5
(c)40
(d) 0
See the attachment for explanation
- Attachments
-
- Venn Diagram
Follow your passion, Success as perceived by others shall follow you