Last visit was: 23 Apr 2026, 01:50 It is currently 23 Apr 2026, 01:50
Home
Messages
Tests
Schools
Events
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 23 Apr 2026
Posts: 109,763
Own Kudos:
810,722
 [7]
Given Kudos: 105,850
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,763
Kudos: 810,722
 [7]
If 1^2+2^2+3^2+...+9^2=285, 3^2+6^2+9^2+12^2+15^2+...+27^2=? 08 Jan 2020, 02:15
Kudos
Add Kudos
7
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

35% (medium)

Question Stats:

71% (01:26) correct 29% (01:55) wrong based on 159 sessions

History

Date
Time
Result
Not Attempted Yet

Competition Mode Question



If \(1^2+2^2+3^2+...+9^2=285\), \(3^2+6^2+9^2+12^2+15^2+...+27^2=?\)

(A) 855
(B) 2,565
(C) 7,695
(D) 23,085
(E) 69,255
ShowHide Answer
Official Answer
B
User avatar
Leadership
User avatar
Retired Moderator
Joined: 17 Dec 2018
Last visit: 21 Jun 2023
Posts: 930
Own Kudos:
526
 [2]
Given Kudos: 73
Status:WHU MBA 2022 candidate
Location: Germany
Concentration: Leadership, Operations
GMAT 1: 650 Q49 V29
WE:Engineering (Manufacturing)
Products:
My Reviews
GMAT 1: 650 Q49 V29
Posts: 930
Kudos: 526
 [2]
If 1^2+2^2+3^2+...+9^2=285, 3^2+6^2+9^2+12^2+15^2+...+27^2=? 08 Jan 2020, 02:44
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
\(1^2+2^2+3^2+...+9^2=285\),
\(3^2+6^2+9^2+12^2+15^2+...+27^2=?\)

Taking \(3^2\) common from \(3^2+6^2+9^2+12^2+15^2+...+27^2\)
We get: \(3^2\)(\(1^2+2^2+3^2+...+9^2\))
replacing the value of \(1^2+2^2+3^2+...+9^2=285\)
\(3^2*285\)
we get 2,565 (B is the Winner)
User avatar
exc4libur
User avatar
Joined: 24 Nov 2016
Last visit: 22 Mar 2022
Posts: 1,680
Own Kudos:
1,469
 [3]
Given Kudos: 607
Location: United States
Posts: 1,680
Kudos: 1,469
 [3]
If 1^2+2^2+3^2+...+9^2=285, 3^2+6^2+9^2+12^2+15^2+...+27^2=? 08 Jan 2020, 04:59
2
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Quote:
If \(1^2+2^2+3^2+...+9^2=285\), \(3^2+6^2+9^2+12^2+15^2+...+27^2=\)?

(A) 855
(B) 2,565
(C) 7,695
(D) 23,085
(E) 69,255
Show more

\(3^2+6^2+9^2+12^2+15^2+...+27^2\)
\(3^2+3^22^2+3^23^2+3^22^4+3^25^2+...+3^23^4\)
\(3^2(1+2^2+3^2+2^4+5^2+2^23^2...+3^4)\)
\(3^2(1+4+9+16+25+36…81)\)
\(3^2(285)=2565\)

Ans (B)
User avatar
ostrick5465
User avatar
Joined: 30 Jul 2019
Last visit: 10 Apr 2026
Posts: 196
Own Kudos:
231
 [1]
Given Kudos: 71
Location: Viet Nam
WE:Education (Education)
Products:
My Reviews
Posts: 196
Kudos: 231
 [1]
If 1^2+2^2+3^2+...+9^2=285, 3^2+6^2+9^2+12^2+15^2+...+27^2=? 08 Jan 2020, 07:44
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
\(3^2+6^2+9^2+12^2+15^2+...+27^2 = 3^2 * ( 1^2 + 2^2 + 3^2 + ... + 9^2) = 9*285 = 2565\)
User avatar
freedom128
User avatar
Joined: 30 Sep 2017
Last visit: 01 Oct 2020
Posts: 939
Own Kudos:
1,377
 [1]
Given Kudos: 402
GMAT 1: 720 Q49 V40
GPA: 3.8
Products:
My Reviews
GMAT 1: 720 Q49 V40
Posts: 939
Kudos: 1,377
 [1]
If 1^2+2^2+3^2+...+9^2=285, 3^2+6^2+9^2+12^2+15^2+...+27^2=? 08 Jan 2020, 08:14
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
1^2 +2^2 +3^2 +... +9^2 = 285
3^2*(1^2 +2^2 +3^2 +... +9^2) = 3^2*285
3^2 +6^2 +9^2 +... +27^2 = 9*285 = 2565

Final answer is (B)

Posted from my mobile device
User avatar
unraveled
User avatar
Joined: 07 Mar 2019
Last visit: 10 Apr 2025
Posts: 2,706
Own Kudos:
2,329
 [1]
Given Kudos: 763
Location: India
WE:Sales (Energy)
Posts: 2,706
Kudos: 2,329
 [1]
If 1^2+2^2+3^2+...+9^2=285, 3^2+6^2+9^2+12^2+15^2+...+27^2=? 08 Jan 2020, 10:10
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
If \(1^2+2^2+3^2+...+9^2=285\), \(3^2+6^2+9^2+12^2+15^2+...+27^2=?\)

(A) 855
(B) 2,565
(C) 7,695
(D) 23,085
(E) 69,255

\(1^2+2^2+3^2+...+9^2=285\)
\(3^2+6^2+9^2+12^2+15^2+...+27^2\)
\((3.1)^2+(3.2)^2+(3.3)^2+(3.4)^2+(3.5)^2+...+(3.9)^2\)
\(3^2(1^2+2^2+3^2+4^2+5^2+...+9^2)\)
9 * 285 = 2565

Answer B.
User avatar
lacktutor
User avatar
Joined: 25 Jul 2018
Last visit: 23 Oct 2023
Posts: 658
Own Kudos:
1,446
 [1]
Given Kudos: 69
Posts: 658
Kudos: 1,446
 [1]
If 1^2+2^2+3^2+...+9^2=285, 3^2+6^2+9^2+12^2+15^2+...+27^2=? 08 Jan 2020, 11:01
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
If \(1^{2}+2^{2}+3^{2}+...+9^{2}=285\) ,
--> \(3^{2}+6^{2}+9^{2}+12^{2}+15^{2}+...+27^{2}\) =?

--> \(3^{2}+6^{2}+9^{2}+12^{2}+15^{2}+...+27^{2}\)= \(3^{2}\)* (\(1^{2}+2^{2}+3^{2}+...+9^{2\))=9*(285)= 2565

The answer is B.
User avatar
Archit3110
User avatar
Major Poster
Joined: 18 Aug 2017
Last visit: 22 Apr 2026
Posts: 8,627
Own Kudos:
5,190
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 Club Tests Forum Quiz
GMAT Focus 2: 645 Q83 V82 DI81
Posts: 8,627
Kudos: 5,190
If 1^2+2^2+3^2+...+9^2=285, 3^2+6^2+9^2+12^2+15^2+...+27^2=? 08 Jan 2020, 18:17
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Given sum of squares = 285
And for given expression we can rewrite as 9*285= 2565 IMOB

Posted from my mobile device
User avatar
Jawad001
User avatar
Joined: 14 Sep 2019
Last visit: 10 Nov 2022
Posts: 216
Own Kudos:
153
 [1]
Given Kudos: 31
Posts: 216
Kudos: 153
 [1]
If 1^2+2^2+3^2+...+9^2=285, 3^2+6^2+9^2+12^2+15^2+...+27^2=? 08 Jan 2020, 22:18
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
We are given that,3^2 + 6^2 + 9^2 + 12^2 + 15^2 +……………………..+27^2
= 1 x 3^2 + 2^2 x 3^2 + 3^2 x 3^2 + 3^2 x 4^2 + 3^2 x 5^2 + ……………+ 3^2 x 9^2
=3^2(1 + 2^2 + 3^2 + 4^2 + 5^2 + ……………+ 9^2)
= 9 x 285(1 + 2^2 + 3^2 + 4^2 + 5^2 + ……………+ 9^2 = 285)
= 2,565(B)
User avatar
eakabuah
User avatar
Retired Moderator
Joined: 18 May 2019
Last visit: 15 Jun 2022
Posts: 774
Own Kudos:
1,144
 [1]
Given Kudos: 101
Posts: 774
Kudos: 1,144
 [1]
If 1^2+2^2+3^2+...+9^2=285, 3^2+6^2+9^2+12^2+15^2+...+27^2=? 09 Jan 2020, 00:22
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
1^2+2^2+3^2+...+9^2=285
3^2+6^2+9^2+12^2+15^2+...+27^2 = 3^2(1^2+2^2+3^2+...+9^2) = 9*285 = 2565

The answer is B.
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,960
Own Kudos:
1,117
Posts: 38,960
Kudos: 1,117
If 1^2+2^2+3^2+...+9^2=285, 3^2+6^2+9^2+12^2+15^2+...+27^2=? 26 Mar 2026, 08:35
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:
Bunuel
Math Expert
109763 posts
Krunaal
Tuck School Moderator
853 posts