Last visit was: 19 Nov 2025, 06:44 It is currently 19 Nov 2025, 06:44
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.
Close
Request Expert Reply
Confirm Cancel
User avatar
KarishmaB
Joined: 16 Oct 2010
Last visit: 18 Nov 2025
Posts: 16,267
Own Kudos:
76,994
 [1]
Given Kudos: 482
Location: Pune, India
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 16,267
Kudos: 76,994
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
sayan640
Joined: 29 Oct 2015
Last visit: 10 Nov 2025
Posts: 1,179
Own Kudos:
Given Kudos: 783
GMAT 1: 570 Q42 V28
Products:
GMAT 1: 570 Q42 V28
Posts: 1,179
Kudos: 813
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
KarishmaB
Joined: 16 Oct 2010
Last visit: 18 Nov 2025
Posts: 16,267
Own Kudos:
76,994
 [1]
Given Kudos: 482
Location: Pune, India
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 16,267
Kudos: 76,994
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
avatar
matteotchodi
Joined: 29 May 2020
Last visit: 07 Jan 2022
Posts: 12
Own Kudos:
Given Kudos: 94
Posts: 12
Kudos: 9
Kudos
Add Kudos
Bookmarks
Bookmark this Post
we need to find MAX - MIN = ?

in order to MAX we need to have as much overlap as possible between the three

in order to MIN we need the least amount of overlap between the three...
start with 80 as it is the biggest value
then going down analyze the gaps that are in the outside and max the amount that you would put in the outside region so that you can minimize the amount that overlaps
Attachments

Capture.JPG
Capture.JPG [ 101.28 KiB | Viewed 4171 times ]

User avatar
carouselambra
User avatar
Current Student
Joined: 14 Mar 2018
Last visit: 28 Apr 2023
Posts: 311
Own Kudos:
Given Kudos: 43
Posts: 311
Kudos: 447
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hi yashikaaggarwal
Just having a little trouble with this one. Need your help.

In a village of 100 households, 75 have at least one DVD player, 80 have at least one cell phone, and 55 have at least one MP3 player. If x and y are respectively the greatest and lowest possible number of households that have all three of these devices, x – y is:

Now,
We are given that we need to 'maximize' the number of households that have all three of these devices.
It will be 100, right? It is given that 55 have at least one MP3 player.
It is very much possible that 100 folks have all the 3 devices.

As for minimum, I am little stuck. It should be 55.
So basically, 100-55= 45.

Is my thinking correct? I didn't use Venn diagrams, equations.
User avatar
yashikaaggarwal
User avatar
Senior Moderator - Masters Forum
Joined: 19 Jan 2020
Last visit: 17 Jul 2025
Posts: 3,086
Own Kudos:
3,103
 [1]
Given Kudos: 1,510
Location: India
GPA: 4
WE:Analyst (Internet and New Media)
Posts: 3,086
Kudos: 3,103
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
sharmashivng
Hi yashikaaggarwal
Just having a little trouble with this one. Need your help.

In a village of 100 households, 75 have at least one DVD player, 80 have at least one cell phone, and 55 have at least one MP3 player. If x and y are respectively the greatest and lowest possible number of households that have all three of these devices, x – y is:

Now,
We are given that we need to 'maximize' the number of households that have all three of these devices.
It will be 100, right? It is given that 55 have at least one MP3 player.
It is very much possible that 100 folks have all the 3 devices.

As for minimum, I am little stuck. It should be 55.
So basically, 100-55= 45.

Is my thinking correct? I didn't use Venn diagrams, equations.
Yeah you are correct with both part, but let's understand the logic
the total is 100
and if we total all DVD users(Only 1, 2 or all 3) + Cell phone users(Only 1, 2 or all 3) + MP3 users(Only 1, 2 or all 3)
that equals to 75+80+55 = 210 which is 110 more than 100
so the largest interaction zone can be 110
BUT,
we can never go more than the original total, and
If we want to maximize those who like all 3, we have to maximize the value in the intersection. So, we have to minimize the value of the union. that can hold upto 100 value.
So, Maximum is 100

Now, Minimum.
If we want to minimize those who like all 3, we have to minimize the value in the intersection. So, we have to maximize the value of the union. the minimum value among all DVD users, Cell phone users, and MP3 users (75,80,55 is 55)
which can be a part of all 3 venn Interaction period at the lowest level
so the minimum value is 55

Difference between maximum and minimum is 100-55 = 45
User avatar
Karthik740
Joined: 20 Oct 2020
Last visit: 18 Jul 2025
Posts: 37
Own Kudos:
Given Kudos: 20
Location: India
Concentration: Strategy, Finance
GMAT 1: 720 Q50 V38
GPA: 4
Products:
GMAT 1: 720 Q50 V38
Posts: 37
Kudos: 77
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Please find below an explanation that will not confuse you but create an easy path to answer such questions -:

Clearly maximum overlap can be 55 (as explained above)
For minimum overlap, we should maximize the 2 sets of people here -:
In total there are - 75 + 80 + 55 = 210
Maximize 2 sets i.e. 100*2 = 200 (we are maximizing 100 households having either 2 of the 3 equipments)
Minimum Overlap = 10

Same logic can be applied in another official question -:
https://gmatclub.com/forum/in-a-certain ... 60789.html
avatar
amoghhlgr
Joined: 16 Jun 2019
Last visit: 19 Jul 2023
Posts: 28
Own Kudos:
Given Kudos: 135
Location: India
Schools: Said'16
GMAT 1: 690 Q44 V40
GPA: 3.5
Schools: Said'16
GMAT 1: 690 Q44 V40
Posts: 28
Kudos: 9
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Okay! Some nice explanations there. Here's my take...

Total Houses: 100.

Houses with DVD player: 75
Houses w/ Cell Phones: 80
Houses w/ MP3s: 55

That's all the data we have. Now we need to find the max and min values of 'g' (remember, that represents the 'all-the-three' block in the Venn Diagram).

Lets focus on the max value of 'g':
If we go on distributing a set of those three gadgets to each house, we'll run out of MP3s after House No. 55. So, we'll stop right there. That's the max number of houses which can have all the three gadgets. (g max = 55)

Lets now focus on the min value of 'g':
We don't have to begin from the start. Let's continue from where we left in our previous step.

55 houses have all the three gadgets. Let's call it Block A. 45 houses are still empty, and this is Block B. We have 80-55 = 25 CD players, and 75-55=20 DVD players left for distribution.

Total gadgets left: 45. Total houses left: 45. Voila! Give each one away to each house left.

Now, let's minimise the no. of houses having all the three gadgets. How can we do that?

None of the houses in Block B have an MP3 player. Okay, lets remove 45 MP3s from the Block A and re-distribute it to Block B.

55-45=10. Just 10 houses now have all the three gadgets.

Focus on the second step, since that is the trickiest part of this solution. Remember, you can't remove any more DVDs or CDs from Block A, since all the houses in Block B have them already. So, you can only remove the MP3s from Block A.

There you go: 55-10 = 45!

Cheers!
User avatar
NakulDiwakar10
Joined: 14 Jun 2021
Last visit: 16 Nov 2025
Posts: 141
Own Kudos:
Given Kudos: 65
Location: India
Products:
Posts: 141
Kudos: 33
Kudos
Add Kudos
Bookmarks
Bookmark this Post
ScottTargetTestPrep JeffTargetTestPrep Please help how to solve and approach this
User avatar
SVaidyaraman
Joined: 17 Dec 2012
Last visit: 11 Jul 2025
Posts: 576
Own Kudos:
Given Kudos: 20
Location: India
Expert
Expert reply
Posts: 576
Kudos: 1,795
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Was just going through the question again.

Isn't the following understanding consistent with the information given in the question?

75 households have at least 1 dvd player, 15 have at least two dvd players and 5 have at least 3 dvd players and so on

Similarly for the other two items.
User avatar
einstein801
Joined: 23 Jan 2024
Last visit: 18 Feb 2025
Posts: 168
Own Kudos:
Given Kudos: 138
Posts: 168
Kudos: 179
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Thank you. This was the most helpful explanation imo.
Let me try to iterate on it.
We have a total of 100 ppl, CD: 80, DVD: 75, MP3: 55.

Lets start with CD and DVD.
- What is the maximum number of people with both CD and DVD? 75. Answer is limited by the smallest number. Example: we have 100 boys and 10 girls. Assuming a couple = 1boy+1girl. Max number of couples is 10.
- I take CD as DVD as a new group X. What is the maximum number of people with X and MP3? 55.
- Therefore max is 55.

- What is the minimum number of people with both CD and DVD? The minimum happens when number of people with just DVD is maximised.
- # of ppl with DVD = 75 = # of ppl with DVD and CP + # of ppl with just DVD
- Since there are only 20 ppl with no CP, this means that the max # of ppl with just DVD is 20
- Hence solving the above equation, min # of ppl with DVD and CP is 75 - 20 =55 = x
- taking DVD and CP as a new group X, the min # of ppl with X is 55.

- What is the min number of ppl with X and MP3? As above, the min happens when number of ppl with only MP3 is maximised
- # of people with MP3 = 55 = # of ppl with MP3 and X + # of ppl with MP3 only
- Since there are only 45 ppl with no X, this means that the max # of ppl with MP3 only is 10
- Hence solving the above equation, min # of ppl with X and MP3 is 55 - 45 = 10 = y

therefore: x-y - 55-10 = 45
rednblack89
For mainhoon and others who still didn't understand, you have to create the situation of minimum possible overlap. This is done in the way Bunuel explains it:

After the first step of distributing phones and DVDs among the 100, you get 55 as the minimum possible overlap for these 2.
Now you bring in the MP3s, of which there are 55. Remember, you are trying to make sure as few people as possible get all 3 - if possible, none. So, what do you do when you have 55 MP3s, and 45 people left who don't have an DVD and a phone? Distribute it among them first, naturally!

After doing that, you still have 10 left over. You are left with no choice but to distribute these among those who already have a DVD and phone. Hence the minimum overlap you can possibly achieve is 10.

This gives you the answer of 55 - 10 = 45.
­
User avatar
renzosm93
Joined: 08 May 2024
Last visit: 06 May 2025
Posts: 23
Own Kudos:
Given Kudos: 19
Location: Peru
GMAT Focus 1: 675 Q84 V84 DI82 (Online)
GPA: 2.4
GMAT Focus 1: 675 Q84 V84 DI82 (Online)
Posts: 23
Kudos: 14
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Try to understand Bunuel explanation. Its brilliant and a time saver.
User avatar
Dbrunik
Joined: 13 Apr 2024
Last visit: 01 Nov 2025
Posts: 270
Own Kudos:
Given Kudos: 267
Location: United States (MN)
Concentration: Finance, Technology
GMAT Focus 1: 625 Q84 V82 DI77
GMAT Focus 1: 625 Q84 V82 DI77
Posts: 270
Kudos: 124
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
Hussain15
In a village of 100 households, 75 have at least one DVD player, 80 have at least one cell phone, and 55 have at least one MP3 player. If x and y are respectively the greatest and lowest possible number of households that have all three of these devices, x – y is:

A. 65

B. 55

C. 45

D. 35

E. 25
For me the best way to solve this problem is not use Venn diagram or formulas but to draw simple bars (note: each dash is 5):

Min overlap is 10:
-------------------- 80 phones;
-------------------- 75 DVD's;
-------------------- 55 MP3.

Max overlap is 55:
-------------------- 80 phones;
-------------------- 75 DVD's;
-------------------- 55 MP3.

55-10=45.

Answer: C.


Finding this the most sense to understand, however once you know, the trick that you can take the sum of the minimums, and then subtract that sum from the end total that that actually becomes the easiest way to find the minimum. So using an understanding these two methods and conjunction, makes this question a lot easier to solve or rather just understand.

Posted from my mobile device
User avatar
DanTheGMATMan
Joined: 02 Oct 2015
Last visit: 18 Nov 2025
Posts: 378
Own Kudos:
Given Kudos: 9
Expert
Expert reply
Posts: 378
Kudos: 226
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The most they could overlap is 55 of course. And for the least, I think it's best to draw lines or venn diagrams where you make the minimum amount of overlap of all 3:

User avatar
Pif96
Joined: 24 Sep 2024
Last visit: 09 Jul 2025
Posts: 15
Own Kudos:
Given Kudos: 262
Posts: 15
Kudos: 3
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hi Karishma,
I find the solution in this way, let me know where i m wrong.....:

Minimum value of households with all three devices --> 55
Max value of households --> 100 ( because the problem can not say that it can not happen.... each household have all devices).
So 100-55 = 45
KarishmaB
suchoudh
VeritasPrepKarishma

Now, minimum number of households: We want to take the circles as far apart from each other as possible. Now put the MP3 households in a way to minimize all three overlap. So put it in the shaded region. You will need to put 10 of the MP3 households in the common area. So minimum overlap is 10.

Ok, and how did you get to the number 10?

(25 + 20 =) 45 households have either only Cell or only DVD Player. Out of the 55 households who have MP3 Players, put 45 in these areas so that all three do not overlap. But the rest of the (55 - 45 =)10 households that have MP3 players need to be put in the common region consisting of 55 households that have both Cell and DVD Player. Hence overlap of all three will be 10.
User avatar
nayanq2001
Joined: 10 Jun 2023
Last visit: 19 Nov 2025
Posts: 5
Own Kudos:
Given Kudos: 130
Posts: 5
Kudos: 5
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Ma'am, why is none 0?
KarishmaB
hiredhanak: I am assuming you are looking for a venn diagram solution to this question..

It is pretty simple.
First of all maximum number of households: We want to bring the circles to overlap as much as possible.
80 - Cell phone
75 - DVD
55 - MP3
Lets take Cell phone and DVD circles since they will have maximum overlap. They must overlap in 55 households so that total number of households is 100. Now put the MP3 households in a way to maximize all three overlap.
Attachment:
Ques1.jpg
So at most 55 households can have all 3.

Now, minimum number of households: We want to take the circles as far apart from each other as possible. Now put the MP3 households in a way to minimize all three overlap. So make the MP3 households occupy the shaded region i.e. region occupied by DVD players alone and cell phone alone. You will be able to adjust 45 MP3s outside the common area but you will need to put 10 of the MP3 households in the common area. So minimum overlap is 10.
Attachment:
Ques2.jpg

x - y = 55 - 10 = 45

Check out this video discussion on how to handle max-min in Sets: https://youtu.be/oLKbIyb1ZrI
avatar
ManifestDreamMBA
Joined: 17 Sep 2024
Last visit: 18 Nov 2025
Posts: 1,282
Own Kudos:
Given Kudos: 236
Products:
Posts: 1,282
Kudos: 785
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I can chime in, the question mentions at least 1 for all the devices: 75 have at least one DVD player, 80 have at least one cell phone, and 55 have at least one MP3 player. So, there no one who has none of the devices

nayanq2001
Ma'am, why is none 0?
KarishmaB
hiredhanak: I am assuming you are looking for a venn diagram solution to this question..

It is pretty simple.
First of all maximum number of households: We want to bring the circles to overlap as much as possible.
80 - Cell phone
75 - DVD
55 - MP3
Lets take Cell phone and DVD circles since they will have maximum overlap. They must overlap in 55 households so that total number of households is 100. Now put the MP3 households in a way to maximize all three overlap.
Attachment:
Ques1.jpg
So at most 55 households can have all 3.

Now, minimum number of households: We want to take the circles as far apart from each other as possible. Now put the MP3 households in a way to minimize all three overlap. So make the MP3 households occupy the shaded region i.e. region occupied by DVD players alone and cell phone alone. You will be able to adjust 45 MP3s outside the common area but you will need to put 10 of the MP3 households in the common area. So minimum overlap is 10.
Attachment:
Ques2.jpg

x - y = 55 - 10 = 45

Check out this video discussion on how to handle max-min in Sets: https://youtu.be/oLKbIyb1ZrI
User avatar
Elsapaul111
Joined: 15 May 2022
Last visit: 24 Jul 2025
Posts: 4
Given Kudos: 57
Posts: 4
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hi, Can we solve this qn using table and Countings method as shown in Qn.3 of this video.?

GMAT Ninja Quant Ep 14: Overlapping Sets

Hussain15
In a village of 100 households, 75 have at least one DVD player, 80 have at least one cell phone, and 55 have at least one MP3 player. If x and y are respectively the greatest and lowest possible number of households that have all three of these devices, x – y is:

A. 65
B. 55
C. 45
D. 35
E. 25
User avatar
iamjatinagrawal
Joined: 03 Jul 2024
Last visit: 19 Nov 2025
Posts: 49
Own Kudos:
Given Kudos: 280
Products:
Posts: 49
Kudos: 17
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Same question but with only a few replacements of the words to make it a different sceanrio: https://gmatclub.com/forum/in-a-company-of-100-employees-75-have-at-laptop-80-have-at-least-one-312092.html
User avatar
sintsunt
Joined: 02 Oct 2025
Last visit: 24 Oct 2025
Posts: 1
Posts: 1
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Same questions too

Elsapaul111
Hi, Can we solve this qn using table and Countings method as shown in Qn.3 of this video.?

GMAT Ninja Quant Ep 14: Overlapping Sets


   1   2   3 
Moderators:
Math Expert
105388 posts
Tuck School Moderator
805 posts