Last visit was: 19 Nov 2025, 05:09 It is currently 19 Nov 2025, 05:09
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
EgmatQuantExpert
User avatar
e-GMAT Representative
Joined: 04 Jan 2015
Last visit: 02 Apr 2024
Posts: 3,663
Own Kudos:
20,164
 [25]
Given Kudos: 165
Expert
Expert reply
Posts: 3,663
Kudos: 20,164
 [25]
2
Kudos
Add Kudos
22
Bookmarks
Bookmark this Post
User avatar
pushpitkc
Joined: 26 Feb 2016
Last visit: 19 Feb 2025
Posts: 2,802
Own Kudos:
6,063
 [2]
Given Kudos: 47
Location: India
GPA: 3.12
Posts: 2,802
Kudos: 6,063
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
avatar
Chhavi28
Joined: 21 Apr 2018
Last visit: 14 Aug 2018
Posts: 1
Own Kudos:
Given Kudos: 23
Posts: 1
Kudos: 1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
EgmatQuantExpert
User avatar
e-GMAT Representative
Joined: 04 Jan 2015
Last visit: 02 Apr 2024
Posts: 3,663
Own Kudos:
20,164
 [4]
Given Kudos: 165
Expert
Expert reply
Posts: 3,663
Kudos: 20,164
 [4]
3
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post

Solution



Given:
    • In the box,
      o Ball point pens = 4
      o Fountain pens = 3

To find:
    • How many possible selections can be formed which have at least 2 items of every types of pen

Approach and Working:
As we have to ensure at least 2 items of every types of pen, the different possible cases and their respective possibilities are as follows:
    • 2 ball point pens and 2 fountain pens = \(^4C_2 * ^3C_2 = 6 * 3 = 18\)
    • 3 ball point pens and 2 fountain pens = \(^4C_3 * ^3C_2 = 4 * 3 = 12\)
    • 4 ball point pens and 2 fountain pens = \(^4C_4 * ^3C_2 = 1 * 3 = 3\)
    • 2 ball point pens and 3 fountain pens = \(^4C_2 * ^3C_3 = 6 * 1 = 6\)
    • 3 ball point pens and 3 fountain pens = \(^4C_3 * ^3C_3 = 4 * 1 = 4\)
    • 4 ball point pens and 3 fountain pens = \(^4C_4 * ^3C_3 = 1 * 1 = 1\)

Therefore, total number of possible selections = 18 + 12 + 3 + 6 + 4 + 1 = 44

Hence, the correct answer is option B.

Answer: B
User avatar
energetics
Joined: 05 Feb 2018
Last visit: 09 Oct 2020
Posts: 297
Own Kudos:
Given Kudos: 325
Posts: 297
Kudos: 941
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The question is asking for the #ways to choose at least 2 b and f pens

For b: For f:
4C0=1, 3C0=1
4C1=4, 3C1=3

4C2=6, 3C2=3
4C3=4, 3C1=1
4C4=1
+ =11,+ = 4

11 ways to chose b*4 ways to choose f = 44
avatar
serenayong
Joined: 20 May 2018
Last visit: 14 Apr 2022
Posts: 18
Own Kudos:
Given Kudos: 12
Schools: LBS '23 (S)
Schools: LBS '23 (S)
Posts: 18
Kudos: 6
Kudos
Add Kudos
Bookmarks
Bookmark this Post
why are we assuming that all the pens are different? It didnt mentioned so in the question.
avatar
Sanjaykumarro
Joined: 05 Jun 2020
Last visit: 26 Oct 2021
Posts: 9
Own Kudos:
Given Kudos: 2
Status:Business
Location: India
Sanjay: Kumar
Schools: CBS '22
WE:Business Development (Consumer Electronics)
Schools: CBS '22
Posts: 9
Kudos: 5
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The question is asking for the #ways to choose at least 2 b and f pens

For b: For f:
4C0=1, 3C0=1
4C1=4, 3C1=3
4C2=6, 3C2=3
4C3=4, 3C1=1
4C4=1
+ =11,+ = 4

11 ways to chose b*4 ways to choose f = 44
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,583
Own Kudos:
Posts: 38,583
Kudos: 1,079
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.
Moderators:
Math Expert
105385 posts
Tuck School Moderator
805 posts