Last visit was: 16 Jul 2025, 17:03 It is currently 16 Jul 2025, 17:03
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
BrentGMATPrepNow
User avatar
Major Poster
Joined: 12 Sep 2015
Last visit: 13 May 2024
Posts: 6,755
Own Kudos:
34,102
 [31]
Given Kudos: 799
Location: Canada
Expert
Expert reply
Posts: 6,755
Kudos: 34,102
 [31]
Kudos
Add Kudos
31
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
Kinshook
User avatar
Major Poster
Joined: 03 Jun 2019
Last visit: 16 Jul 2025
Posts: 5,703
Own Kudos:
5,226
 [6]
Given Kudos: 161
Location: India
GMAT 1: 690 Q50 V34
WE:Engineering (Transportation)
Products:
GMAT 1: 690 Q50 V34
Posts: 5,703
Kudos: 5,226
 [6]
1
Kudos
Add Kudos
5
Bookmarks
Bookmark this Post
General Discussion
User avatar
shameekv1989
Joined: 14 Dec 2019
Last visit: 17 Jun 2021
Posts: 820
Own Kudos:
966
 [1]
Given Kudos: 354
Location: Poland
Concentration: Entrepreneurship, Strategy
GMAT 1: 640 Q49 V27
GMAT 2: 660 Q49 V31
GMAT 3: 720 Q50 V38
GPA: 4
WE:Engineering (Consumer Electronics)
Products:
GMAT 3: 720 Q50 V38
Posts: 820
Kudos: 966
 [1]
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
User avatar
BrentGMATPrepNow
User avatar
Major Poster
Joined: 12 Sep 2015
Last visit: 13 May 2024
Posts: 6,755
Own Kudos:
34,102
 [3]
Given Kudos: 799
Location: Canada
Expert
Expert reply
Posts: 6,755
Kudos: 34,102
 [3]
2
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
GMATPrepNow
What is the remainder when \(3^{32}\) is divided by 82?

A) 0
B) 1
C) 8
D) 9
E ) 81

Here's an approach that doesn't involve modular arithmetic....

If we recognize that 82 is 1 greater than 81 (aka \(3^4\)), then we might see that 82 is a divisor of \(3^{32} - 1\)
Here's why:

\(3^{32} - 1 = (3^{16} + 1)(3^{16} - 1)\)
\(= (3^{16} + 1)(3^8 + 1)(3^8 - 1)\)
\(= (3^{16} + 1)(3^8 + 1)(3^4 - 1)(3^4 + 1)\)
\(= (3^{16} + 1)(3^8 + 1)(3^4 - 1)(82)\)

This tells us that \((3^{32} - 1)\) is a multiple of 82...
...and this means \(3^{32}\) is 1 greater than a multiple of 82, which means we'll get a remainder of 1 when we divide \(3^{32}\) by 82

Answer: B

Cheers,
Brent
avatar
jamiedimonn
Joined: 12 Jul 2024
Last visit: 12 Jul 2025
Posts: 34
Own Kudos:
3
 [1]
Given Kudos: 40
Posts: 34
Kudos: 3
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
@Bkarishma, Bunuel or any other expert could you please explain why ans is B...


i did (3^4)^8 which makes it 81/82 which tells us that quotient is 0 and remainder is 81 making it answer E BUT WHY ANS IS B??
User avatar
Krunaal
User avatar
PS Forum Moderator
Joined: 15 Feb 2021
Last visit: 16 Jul 2025
Posts: 697
Own Kudos:
Given Kudos: 243
Status:Under the Square and Compass
Location: India
WE:Marketing (Internet and New Media)
Products:
Posts: 697
Kudos: 727
Kudos
Add Kudos
Bookmarks
Bookmark this Post
jamiedimonn
remainder is 81 . when 81 /82 quotient is 0 remainder is 81 why ans is B . EXPLAIN THIS -1 CONCEPT ,PLEASE
Kinshook
GMATPrepNow
What is the remainder when \(3^{32}\) is divided by 82?

A) 0
B) 1
C) 8
D) 9
E ) 81

Asked: What is the remainder when \(3^{32}\) is divided by 82?

Remainder when 3^4 = 81 is divided by 82 = - 1
Remainder when (3^4)^8 is divided by 82 = (-1)^8 = 1

IMO B

We are dividing \(81^8\) by \(82\) and not \(81^1\) by \(82\),

When we divide \(81^1\) by \(82\), we get \((-1)^1\) = \(-1\) but as remainder cannot be negative we add divisor \(82 \) to it => \(-1 + 82 = 81\) thus \(81\) becomes the remainder.

But when we divide \(81^8\) by \(82\), we get \((-1)^8 = 1\), and \(1\) can be a remainder.

Here's more on the concept of negative remainders => All about negative remainders on GMAT
Moderators:
Math Expert
102594 posts
PS Forum Moderator
697 posts