Find all School-related info fast with the new School-Specific MBA Forum

It is currently 02 Sep 2014, 11:10

Close

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

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

PS - sets ques (with percents)

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
User avatar
Joined: 14 May 2007
Posts: 175
Location: India
Followers: 2

Kudos [?]: 32 [0], given: 11

GMAT Tests User
PS - sets ques (with percents) [#permalink] New post 16 Jun 2008, 05:31
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Hello Everyone,

I came across this question and I am posting it. Though it is a re-post but I need an additional clarification.

Q-1 In a consumer survey, 85% of those surveyed liked at least one of three products: 1, 2, and 3. 50% of those asked liked product 1, 30% liked product 2, and 20% liked product 3. If 5% of the people in the survey liked all three of the products, what percentage of the survey participants liked more than one of the three products?

A) 5
B) 10
C) 15
D) 20
E) 25

OA IS B

My theory: I came across another sets problem where one of the gmatclub member came up with the following formula -

[ OLD SETS QUES SOL
Set up a venn diagram with the following:
#(all three) = 3
#(basketball and baseball) = x
#(basketball and soccer) = y
#(soccer and baseball) = z
So x+y+z = 27
#(none) = n

63-x-z + 42-x-y + 39-y-z + x + y + z + 3 + n= 150
147-x-y-z+n= 150
147 - (x+y+z) + n = 150
147 - (27) + n = 150
n = 30 ]


Now if I use a similar approach then i should get answer -

solving as per logic mentioned above-
x = 1 IN 2 (IN=intersection)
y = 2 IN 3
z = 1 IN 3

n = none

85 = (50-x-z) + (30-x-y) + (20-z-y) + x+y+z + 5 + n
85 = 50-x-z + 30-x-y + 20-z-y + x+y+z +5 +n
85 = 105 -x - y - z + n
-20 = -x -y -z + n
or 20 = x + y + z - n

Now what should I do ???
Is my approach ok. (gets confused in such type of ques)

Help appreciated,

Cheers,
GR
Kaplan Promo CodeKnewton GMAT Discount CodesGMAT Pill GMAT Discount Codes
Manager
Manager
User avatar
Joined: 20 Mar 2008
Posts: 160
Location: USA
Followers: 1

Kudos [?]: 26 [0], given: 0

Re: PS - sets ques (with percents) [#permalink] New post 16 Jun 2008, 07:08
Here is diagrammatic approach and I get 10 (B).



We could get the same answer by putting 5 in 1 intersection 3 or 3 intersection 2
Attachments

Sets1.doc [24 KiB]
Downloaded 69 times

To download please login or register as a user

Manager
Manager
User avatar
Joined: 14 May 2007
Posts: 175
Location: India
Followers: 2

Kudos [?]: 32 [0], given: 11

GMAT Tests User
Re: PS - sets ques (with percents) [#permalink] New post 16 Jun 2008, 07:25
vishy007 wrote:
Here is diagrammatic approach and I get 10 (B).



We could get the same answer by putting 5 in 1 intersection 3 or 3 intersection 2


Sorry, the explanation was not helpful in getting hang of the issue. :(
Director
Director
avatar
Joined: 27 May 2008
Posts: 552
Followers: 5

Kudos [?]: 171 [0], given: 0

GMAT Tests User
Re: PS - sets ques (with percents) [#permalink] New post 16 Jun 2008, 07:46
greatchap wrote:
Hello Everyone,

I came across this question and I am posting it. Though it is a re-post but I need an additional clarification.

Q-1 In a consumer survey, 85% of those surveyed liked at least one of three products: 1, 2, and 3. 50% of those asked liked product 1, 30% liked product 2, and 20% liked product 3. If 5% of the people in the survey liked all three of the products, what percentage of the survey participants liked more than one of the three products?

A) 5
B) 10
C) 15
D) 20
E) 25

OA IS B

My theory: I came across another sets problem where one of the gmatclub member came up with the following formula -

[ OLD SETS QUES SOL
Set up a venn diagram with the following:
#(all three) = 3
#(basketball and baseball) = x
#(basketball and soccer) = y
#(soccer and baseball) = z
So x+y+z = 27
#(none) = n

63-x-z + 42-x-y + 39-y-z + x + y + z + 3 + n= 150
147-x-y-z+n= 150
147 - (x+y+z) + n = 150
147 - (27) + n = 150
n = 30 ]


Now if I use a similar approach then i should get answer -

solving as per logic mentioned above-
x = 1 IN 2 (IN=intersection)
y = 2 IN 3
z = 1 IN 3

n = none

85 = (50-x-z) + (30-x-y) + (20-z-y) + x+y+z + 5 + n
85 = 50-x-z + 30-x-y + 20-z-y + x+y+z +5 +n
85 = 105 -x - y - z + n
-20 = -x -y -z + n
or 20 = x + y + z - n

Now what should I do ???
Is my approach ok. (gets confused in such type of ques)

Help appreciated,

Cheers,
GR


You approach is perfect,
we know n = 0, becasue in 85 you are taking only those consumers who like at least one of the products.

x+y+z = 20.

Now we have to find out number of consumers (assuming total is 100) who like more than 2 products.
5 is the number of consumers who like all three, lets call it "t"

Now here is the key, In summation if 1IN2, 2IN3 and 3IN1 (x+y+z) we are actually counting 't' 3 times. while for answer we have to count it only once.

So answer = x+y+z - 2t = 20 - 10 = 10.

HTH.
Manager
Manager
User avatar
Joined: 14 May 2007
Posts: 175
Location: India
Followers: 2

Kudos [?]: 32 [0], given: 11

GMAT Tests User
Re: PS - sets ques (with percents) [#permalink] New post 16 Jun 2008, 10:23
Thanks a lot, durgesh79. Now I understood the problem. thanks again... :)

Just one ques, above we got x+y+z = 20 which we got. This 20 is no of people who like at least one product. Am I right?
Director
Director
avatar
Joined: 27 May 2008
Posts: 552
Followers: 5

Kudos [?]: 171 [0], given: 0

GMAT Tests User
Re: PS - sets ques (with percents) [#permalink] New post 16 Jun 2008, 10:57
greatchap wrote:
Thanks a lot, durgesh79. Now I understood the problem. thanks again... :)

Just one ques, above we got x+y+z = 20 which we got. This 20 is no of people who like at least one product. Am I right?


the no of people who like at least one product is 85.

x+y+z = 20. this is the sum of number of people in 3 groups.
People who like both 1 and 2 - (this group includes some people who like 3 also, we know this number is 5)
people who like both 2 and 3 - (this group includes some people who like 1 also, we know this number is 5)
people who like both 3 and 1 - (this group includes some people who like 2 also, we know this number is 5)

So in the sum 20, we have taken this group of 5 people three times.
Manager
Manager
User avatar
Joined: 11 Apr 2008
Posts: 129
Location: Chicago
Followers: 1

Kudos [?]: 31 [0], given: 0

Re: PS - sets ques (with percents) [#permalink] New post 16 Jun 2008, 12:11
greatchap wrote:
Hello Everyone,

I came across this question and I am posting it. Though it is a re-post but I need an additional clarification.

Q-1 In a consumer survey, 85% of those surveyed liked at least one of three products: 1, 2, and 3. 50% of those asked liked product 1, 30% liked product 2, and 20% liked product 3. If 5% of the people in the survey liked all three of the products, what percentage of the survey participants liked more than one of the three products?

A) 5
B) 10
C) 15
D) 20
E) 25

OA IS B



Here is an easier way of looking at this problem (and which has many applications toward other problems of the same type). Using the following formula
A + B + C – AB – AC- BC – 2ABC + Neither = Total ...we want to find AB + AC + BC + ABC --> this is the same as the number of participants who liked at least one of the three products.
Interpretation:
AB: # of participants who liked only A and B
AC: # of participants who liked only A and C
BC: # of participants who liked only B and C
ABC: # of participants who liked A, B and C only.

Filling this formula in with the given information we get:
50 + 30 + 20 – AB – AC – BC – 2(5) + 15 = 100
Interpretation:
50 --> A
30 --> B
20 --> C
2(5) --> 2 * ABC
15 --> Neither (which is just 100-85 = neither)

Solving for AB, AC, and BC they all sum to 5 and when you add in the ABC portion, which is 5, we get 10 as the answer.

I hope this makes sense. Let me know if it doesn't.
_________________

Factorials were someone's attempt to make math look exciting!!!

Manager
Manager
User avatar
Joined: 14 May 2007
Posts: 175
Location: India
Followers: 2

Kudos [?]: 32 [0], given: 11

GMAT Tests User
Re: PS - sets ques (with percents) [#permalink] New post 16 Jun 2008, 19:38
Allright, now I get it. Earlier on, I made silly mistake.

Thanks a ton guys...
Re: PS - sets ques (with percents)   [#permalink] 16 Jun 2008, 19:38
    Similar topics Author Replies Last post
Similar
Topics:
2 PS Sets Ques greatchap 5 18 Jun 2008, 01:39
2 PS Ques (Set 31) greatchap 2 31 Mar 2008, 01:54
Percent ques greatchap 2 11 Dec 2007, 09:54
SET 21 - Ques 13 s_positive 8 19 Oct 2007, 12:01
ps ques perezhan 2 16 Mar 2005, 18:21
Display posts from previous: Sort by

PS - sets ques (with percents)

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.