Last visit was: 23 Apr 2026, 03:01 It is currently 23 Apr 2026, 03:01
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: 23 Apr 2026
Posts: 109,769
Own Kudos:
Given Kudos: 105,853
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,769
Kudos: 810,727
 [13]
1
Kudos
Add Kudos
12
Bookmarks
Bookmark this Post
User avatar
Archit3110
User avatar
Major Poster
Joined: 18 Aug 2017
Last visit: 23 Apr 2026
Posts: 8,628
Own Kudos:
5,190
 [2]
Given Kudos: 243
Status:You learn more from failure than from success.
Location: India
Concentration: Sustainability, Marketing
GMAT Focus 1: 545 Q79 V79 DI73
GMAT Focus 2: 645 Q83 V82 DI81
GPA: 4
WE:Marketing (Energy)
Products:
GMAT Focus 2: 645 Q83 V82 DI81
Posts: 8,628
Kudos: 5,190
 [2]
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
avatar
Bharti123
Joined: 28 Aug 2019
Last visit: 10 Nov 2019
Posts: 2
Own Kudos:
4
 [3]
Posts: 2
Kudos: 4
 [3]
2
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
User avatar
EgmatQuantExpert
User avatar
e-GMAT Representative
Joined: 04 Jan 2015
Last visit: 02 Apr 2024
Posts: 3,657
Own Kudos:
20,865
 [1]
Given Kudos: 165
Expert
Expert reply
Posts: 3,657
Kudos: 20,865
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post

Solution



Given

    • x, y and z are different positive integers
    • \(24x^3y^3z^3\) is a square of an integer

To find

    • Lowest common multiple of x, y and z
Approach
• \(2^4x^3y^3z^3\)= Perfect Square = \(N^2\)
• \(2^3 × 3 × x^3y^3z^3\)= \(N^2\)
• \(2 × 3 × 2^2 × x^3y^3z^3\)= \(N^2\)
• \(2 × 3 × 2^2 × (xyz)^3\)= \(N^2\)
• \(2^2\) is already a perfect square. Hence, 6 × \((xyz)^3\) must be a perfect square.
Therefore, (xyz)^3 must be of the form 6 * some perfect square for 6 × \((xyz)^3\) to be a perfect square.

Therefore, option D is the correct answer.
User avatar
kungfury42
Joined: 07 Jan 2022
Last visit: 31 May 2023
Posts: 580
Own Kudos:
Given Kudos: 724
Schools: NUS '25 (A)
GMAT 1: 740 Q51 V38
GPA: 4
Products:
Schools: NUS '25 (A)
GMAT 1: 740 Q51 V38
Posts: 580
Kudos: 518
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
x, y and z are different positive integers. If \(24x^3y^3z^3\) is a square of an integer, what is the lowest common multiple of x, y and z?

A. 1
B. 2
C. 3
D. 6
E. 12
Bunuel, I think the question needs a bit of fixing. The question should ideally read which of the following could be a lowest common multiple of x, y, and z. Because x=10, y=15, and z=25 also satisfy the condition that \(24x^3y^3z^3\) is a square of an integer, but the LCM of (10, 15, 25) = 150 is not an option :) similarly there can be infinitely many combinations­
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,959
Own Kudos:
Posts: 38,959
Kudos: 1,117
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Math Expert
109766 posts
Tuck School Moderator
853 posts