Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 29 May 2017, 15:22

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# can anyone explain this clearly ?

 post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
Manager
Joined: 25 Mar 2008
Posts: 106
Followers: 1

Kudos [?]: 12 [0], given: 0

can anyone explain this clearly ? [#permalink]

### Show Tags

03 Apr 2008, 08:16
1
This post was
BOOKMARKED
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

GMAT prep

DS Question:
If n and m are positive integers, what is the remainder when 3^(4n+2) + m is divided by 10.

(1) n = 2
(2) m = 1

pls explain this clearly
CEO
Joined: 17 Nov 2007
Posts: 3585
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 576

Kudos [?]: 3989 [1] , given: 360

Re: can anyone explain this clearly ? [#permalink]

### Show Tags

03 Apr 2008, 08:45
1
KUDOS
Expert's post
Ok.

1. It is obviously that with knowledge of n and m we will have one integer and one reminder. So, C works good. But what about A and B? Maybe GMAT want to trick us with C-Trap?

2. take a look on m. It is definitely clear that at m=2 and m=3 we will have different reminders. So the second condition is necessary.

3. What about the first condition? First of all we have 4*n instead of n and it is a small prompt to dig deeper.

4. What do the reminder mean here? when we divide an integer by 10 we will get a reminder that is equal to the unit digit of the integer. So, the unit digit.....and power......

5. Let write unit digits of some powers of 3:

3^0=1
3^1=3
3^2=9
3^3=7
3^4=1
3^5=3
3^6=9
3^7=7

6. What do we see here? period 4 !!! the unit digit is defined by the reminder of the power divided by 4. Actually reminder of 4n+2 is always 2. So, we have found a trap! the answer is B
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

Senior Manager
Joined: 20 Dec 2004
Posts: 254
Followers: 6

Kudos [?]: 107 [0], given: 0

Re: can anyone explain this clearly ? [#permalink]

### Show Tags

03 Apr 2008, 15:21
Walker,

You really have a lot of patience...hats off to you...

+1 for all your hard work and support to the forum...

Thanks a ton!!!
_________________

Stay Hungry, Stay Foolish

Re: can anyone explain this clearly ?   [#permalink] 03 Apr 2008, 15:21
Display posts from previous: Sort by

# can anyone explain this clearly ?

 post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group and phpBB SEO Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.