Last visit was: 26 Apr 2026, 16:41 It is currently 26 Apr 2026, 16:41
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: 26 Apr 2026
Posts: 109,910
Own Kudos:
811,439
 [8]
Given Kudos: 105,897
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,910
Kudos: 811,439
 [8]
Kudos
Add Kudos
8
Bookmarks
Bookmark this Post
User avatar
Purnank
Joined: 05 Jan 2024
Last visit: 26 Apr 2026
Posts: 680
Own Kudos:
615
 [2]
Given Kudos: 167
Location: India
Concentration: General Management, Strategy
GMAT Focus 1: 635 Q88 V76 DI80
Products:
GMAT Focus 1: 635 Q88 V76 DI80
Posts: 680
Kudos: 615
 [2]
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
User avatar
Nidzo
Joined: 26 Nov 2019
Last visit: 02 Aug 2025
Posts: 958
Own Kudos:
1,478
 [2]
Given Kudos: 59
Location: South Africa
Posts: 958
Kudos: 1,478
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
GMATinsight
User avatar
Major Poster
Joined: 08 Jul 2010
Last visit: 26 Apr 2026
Posts: 6,977
Own Kudos:
Given Kudos: 128
Status:GMAT/GRE Tutor l Admission Consultant l On-Demand Course creator
Location: India
GMAT: QUANT+DI EXPERT
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
WE:Education (Education)
Products:
Expert
Expert reply
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
Posts: 6,977
Kudos: 16,922
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
­Alan has a flock of sheep from which he will choose 4 to take with him to the livestock show in Houston. If Alan has 15 distinct possible groups of sheep he could take to the show, then which of the following is the number of sheep in his flock?

A. 30
B. 15
C. 7
D. 6
E. 5


Let's assume he has x sheeps in the flock

Since he has to take 4 in the show, therefore number of ways of choosing 4 out of x sheeps = xC4
­
Given, xC4 = 15

Since 15 isn't too big a numbe as total possible outcomes so let's start substituting some probable values of x instead of solving Algebraically

5C4 = 5
6C4 = 15
ie. x = 6

Answer: Option D
User avatar
luisdicampo
Joined: 10 Feb 2025
Last visit: 19 Apr 2026
Posts: 480
Own Kudos:
Given Kudos: 328
Products:
Posts: 480
Kudos: 75
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Deconstructing the Question

We are given that selecting 4 sheep from a total flock of \(n\) results in 15 distinct groups. This is a combinations problem where order does not matter.

1. Set up the Equation
\(nC4 = 15\)
The formula for \(nC4\) is:
\((n * (n-1) * (n-2) * (n-3)) / (4 * 3 * 2 * 1) = 15\)

2. Strategic Approach: Backsolving
Rather than solving a polynomial, we test the answer choices. Since we are picking 4, \(n\) must be at least 4.

  • Testing E (5): \(5C4 = 5C1 = 5\). Too low.
  • Testing D (6): \(6C4 = 6C2 = (6 * 5) / (2 * 1) = \) 15. Matches!

3. Verification
If \(n = 6\), the number of ways to choose 4 sheep is indeed 15.

The correct answer is (D) .
Moderators:
Math Expert
109910 posts
Tuck School Moderator
852 posts