Last visit was: 14 Jul 2025, 17:45 It is currently 14 Jul 2025, 17:45
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
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 14 Jul 2025
Posts: 102,570
Own Kudos:
Given Kudos: 98,182
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 102,570
Kudos: 741,414
 [11]
Kudos
Add Kudos
11
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
chetan2u
User avatar
GMAT Expert
Joined: 02 Aug 2009
Last visit: 14 Jul 2025
Posts: 11,294
Own Kudos:
41,743
 [4]
Given Kudos: 333
Status:Math and DI Expert
Products:
Expert
Expert reply
Posts: 11,294
Kudos: 41,743
 [4]
2
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
General Discussion
User avatar
DavidTutorexamPAL
User avatar
examPAL Representative
Joined: 07 Dec 2017
Last visit: 09 Sep 2020
Posts: 1,035
Own Kudos:
1,948
 [1]
Given Kudos: 26
Posts: 1,035
Kudos: 1,948
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
PKN
Joined: 01 Oct 2017
Last visit: 22 Jan 2025
Posts: 816
Own Kudos:
Given Kudos: 41
Status:Learning stage
WE:Supply Chain Management (Energy)
Posts: 816
Kudos: 1,543
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
Joe’s pie shop serves only chocolate pies and coconut cream pies. On a given day, Joe sold 200 pies, with each customer buying either one coconut cream pie, one chocolate pie, or one of each. If 80 customers bought both a coconut cream and a chocolate pie, how many chocolate pies did Joe sell?

(1) 40 customers did not buy a chocolate pie.
(2) 120 customers bought a coconut cream pie.

Please refer the affixed diagram.

St1:-Customers who didn’t buy chocolate pie=customers who bought only coconut pie=b=40
Customers who bought chocolate pie=a+c=200-40=160
So, Joe sold 160 nos. of chocolate pies.
Sufficient.
St2:- 120 customers bought coconut pie, b + c=120 or, b=120-80=40
So, a+c=200-b=200-40=160.
So, Joe sold 160 nos. of chocolate pies.
Sufficient.

Ans. (D)
Attachments

Cream pie.JPG
Cream pie.JPG [ 23.88 KiB | Viewed 5986 times ]

avatar
gioacchinorossini
Joined: 21 Feb 2015
Last visit: 18 Oct 2024
Posts: 3
Own Kudos:
Posts: 3
Kudos: 2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Davidtutor's explanation is correct, even if not very detailed. The other explanations saying that the result is 160 are wrong.
They confuse pies and clients.
200 are pies, but the rest of the numbers refer to clients.
So if 80 clients bought both, it means that we have 80 choc pies and 80 coco pies.
200-2x80= 40 remaining pies.

St1) 40 didnt buy choc, so bought only coco, so the 40 remaining pies are all coco, and the choc are 80
st2) 120 bought a coco. Minus the 80 who bought both, we have 40 that bought only coco, and the choc are 80.

Answer D.
User avatar
PKN
Joined: 01 Oct 2017
Last visit: 22 Jan 2025
Posts: 816
Own Kudos:
Given Kudos: 41
Status:Learning stage
WE:Supply Chain Management (Energy)
Posts: 816
Kudos: 1,543
Kudos
Add Kudos
Bookmarks
Bookmark this Post
gioacchinorossini
Davidtutor's explanation is correct, even if not very detailed. The other explanations saying that the result is 160 are wrong.
They confuse pies and clients.
200 are pies, but the rest of the numbers refer to clients.
So if 80 clients bought both, it means that we have 80 choc pies and 80 coco pies.
200-2x80= 40 remaining pies.

St1) 40 didnt buy choc, so bought only coco, so the 40 remaining pies are all coco, and the choc are 80
st2) 120 bought a coco. Minus the 80 who bought both, we have 40 that bought only coco, and the choc are 80.

Answer D.

Hi gioacchinorossini,
Please go through Davidtutor's explanation again, it says 160 #customers bought chocolate pies.
avatar
gioacchinorossini
Joined: 21 Feb 2015
Last visit: 18 Oct 2024
Posts: 3
Own Kudos:
Posts: 3
Kudos: 2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
PKN
gioacchinorossini
Davidtutor's explanation is correct, even if not very detailed. The other explanations saying that the result is 160 are wrong.
They confuse pies and clients.
200 are pies, but the rest of the numbers refer to clients.
So if 80 clients bought both, it means that we have 80 choc pies and 80 coco pies.
200-2x80= 40 remaining pies.

St1) 40 didnt buy choc, so bought only coco, so the 40 remaining pies are all coco, and the choc are 80
st2) 120 bought a coco. Minus the 80 who bought both, we have 40 that bought only coco, and the choc are 80.

Answer D.

Hi
Please go through Davidtutor's explanation again, it says 160 #customers bought chocolate pies.

Dear PKN, I dont see where Davidtutor says "160 #customers bought chocolate pies" (that would be wrong).
His explanation is correct in my opinion. The other explanations of the other users are wrong (even if they come to the same answer D).
User avatar
PKN
Joined: 01 Oct 2017
Last visit: 22 Jan 2025
Posts: 816
Own Kudos:
Given Kudos: 41
Status:Learning stage
WE:Supply Chain Management (Energy)
Posts: 816
Kudos: 1,543
Kudos
Add Kudos
Bookmarks
Bookmark this Post
[/quote]
Dear PKN, I dont see where Davidtutor says "160 #customers bought chocolate pies" (that would be wrong).
His explanation is correct in my opinion. The other explanations of the other users are wrong (even if they come to the same answer D).[/quote]

Hi gioacchinorossini
Extended explanation:-

2 overlapping sets can always be broken into the same 4 categories (both, only A, only B, neither).
This is a Precise approach.

total number of pies= 200
(both chocolate and cocount) = 80
neither = 0 as all customers bought at least one pie
so (only chocolate) + (only cococunt) = total - (both) - (neither) = 200 - 80 - 0 = 120
question - how much is (only chocolate) + (both chocolate and coconut)?

Since we know that (only chocolate) + (only coconut) = 120,----(1) all we need to is the value of (only coconut).

(1) then these 40 must have bought a cococunt pie meaning that (only coconut) = 40. Exactly what we need!

Now, from eq(1), Only chocoloate=120-40=80
Therefore, (only chocolate) + (both chocolate and coconut)=80+80=160
Sufficient.

(2) gives us (only coconut) + (both). Since we know that (both) = 80, we can calculate (only coconut).
So, Only Coconut=120-80=40
Now, from eq(1), Only chocoloate=120-40=80
Therefore, (only chocolate) + (both chocolate and coconut)=80+80=160
Sufficient.

Note:- In DS questions, exact computation is not required. Mr. David did the same thru reasoning, final answer(numerical value) is not required , only data sufficiency is checked.
avatar
gioacchinorossini
Joined: 21 Feb 2015
Last visit: 18 Oct 2024
Posts: 3
Own Kudos:
2
 [2]
Posts: 3
Kudos: 2
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I disagree. There are no choco-coco pies. The pies are either choco or coco. But the clients can buy coco or choco or both. That's why I said that all explanations, apart from the David's one, are wrong, because they confuse clients and pies, and they add clients and pies. I know that in DS you dont need to get the result, I am a GMAT tutor since 2009. Still, if we want to find the answer as if it were PS, it is 80 and not 160.
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 37,399
Own Kudos:
Posts: 37,399
Kudos: 1,013
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Moderator:
Math Expert
102570 posts