Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 02 Jul 2016, 03:30

### 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

# When positive integer n is divided by 3 the remainder is 2;

Author Message
Senior Manager
Joined: 24 Feb 2008
Posts: 348
Schools: UCSD ($) , UCLA, USC ($), Stanford
Followers: 168

Kudos [?]: 2494 [0], given: 2

When positive integer n is divided by 3 the remainder is 2; [#permalink]

### Show Tags

11 May 2008, 19:37
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

When positive integer n is divided by 3 the remainder is 2; and when positive integer t is divided by 5 the remainder is 3. What is the remainder when the product tn is divided by 15?

1) n-2 is divisible by 5
2) t is divisible by 3
_________________

Best AWA guide here: http://gmatclub.com/forum/how-to-get-6-0-awa-my-guide-64327.html

CEO
Joined: 29 Mar 2007
Posts: 2583
Followers: 19

Kudos [?]: 345 [0], given: 0

### Show Tags

13 May 2008, 06:58
chineseburned wrote:
When positive integer n is divided by 3 the remainder is 2; and when positive integer t is divided by 5 the remainder is 3. What is the remainder when the product tn is divided by 15?

1) n-2 is divisible by 5
2) t is divisible by 3

E.

Try values: 17, 27, and 32 for N. And anything divisible by 3 for t. Id start w/ 3.
Senior Manager
Joined: 24 Feb 2008
Posts: 348
Schools: UCSD ($) , UCLA, USC ($), Stanford
Followers: 168

Kudos [?]: 2494 [0], given: 2

### Show Tags

13 May 2008, 10:58
GMATBLACKBELT wrote:
chineseburned wrote:
When positive integer n is divided by 3 the remainder is 2; and when positive integer t is divided by 5 the remainder is 3. What is the remainder when the product tn is divided by 15?

1) n-2 is divisible by 5
2) t is divisible by 3

E.

Try values: 17, 27, and 32 for N. And anything divisible by 3 for t. Id start w/ 3.

27 is divisible by 3 and therefore cannot be N.

Plugging n=17 and t=3 -> tn=51 -> 51/15 -> r=6
Plugging n=32 and t=3 -> tn=96 -> 96/15 -> r=6
Plugging n=17 and t=18 -> tn=306 -> 306/15 -> r=6

OA is C.

But plugging numbers like this takes way longer than 2-3 min since you don't have many options to deal with simple numbers.
Does anyone have a shorter solution?
_________________

Best AWA guide here: http://gmatclub.com/forum/how-to-get-6-0-awa-my-guide-64327.html

Director
Joined: 01 May 2007
Posts: 792
Followers: 1

Kudos [?]: 221 [0], given: 0

### Show Tags

13 May 2008, 11:01
ManhattanGMAT has one, http://www.manhattangmat.com/forums/post10151.html

But even it seems to long...unless someone has a faster way than this.
CEO
Joined: 29 Mar 2007
Posts: 2583
Followers: 19

Kudos [?]: 345 [0], given: 0

### Show Tags

13 May 2008, 12:47
chineseburned wrote:
GMATBLACKBELT wrote:
chineseburned wrote:
When positive integer n is divided by 3 the remainder is 2; and when positive integer t is divided by 5 the remainder is 3. What is the remainder when the product tn is divided by 15?

1) n-2 is divisible by 5
2) t is divisible by 3

E.

Try values: 17, 27, and 32 for N. And anything divisible by 3 for t. Id start w/ 3.

27 is divisible by 3 and therefore cannot be N.

Plugging n=17 and t=3 -> tn=51 -> 51/15 -> r=6
Plugging n=32 and t=3 -> tn=96 -> 96/15 -> r=6
Plugging n=17 and t=18 -> tn=306 -> 306/15 -> r=6

OA is C.

But plugging numbers like this takes way longer than 2-3 min since you don't have many options to deal with simple numbers.
Does anyone have a shorter solution?

arghhh... serves me right for doing this in my head
Manager
Joined: 27 Mar 2008
Posts: 81
Followers: 1

Kudos [?]: 63 [0], given: 0

### Show Tags

13 May 2008, 13:40
I wonder if my approach was too basic and simple...

I plugged in n=5, t=8

Remainder of tn/15= 10

plugged in n and t into statements (1) & (2) and found both insufficient.

I still got E as the answer but is there a step I'm missing? (Even if answer is correct, if the approach is incorrect it doesnt help)

chineseburned wrote:
When positive integer n is divided by 3 the remainder is 2; and when positive integer t is divided by 5 the remainder is 3. What is the remainder when the product tn is divided by 15?

1) n-2 is divisible by 5
2) t is divisible by 3
Manager
Joined: 28 Sep 2007
Posts: 213
Followers: 1

Kudos [?]: 17 [0], given: 0

### Show Tags

13 May 2008, 15:33
ok t cannot =3

3/5 does not equal x Remainder 3.

am i wrong here?

but it still seems to be C.
Senior Manager
Joined: 07 Jan 2008
Posts: 297
Followers: 1

Kudos [?]: 34 [0], given: 0

### Show Tags

19 May 2008, 05:45
From the question stem:

Possible value of n = 2, 5, 8, 11, 14, 17, 20, 23, 26, 29, 32,... ----------I
Possible valud of t = 3, 8, 13, 18, 23, 28, 33, 38, 43.... ----------II

1) n-2 is divisible by 5; So use (I) to get filtered value of n
n = 2, 17, 32,...
not sufficient

2) t is divisible by 3; from (II) get the new filtered value of t
t = 3, 18, 33, ...
not sufficient

Together:
the remainder could be 6 [2*3/15] or 2[17*18/15] or 1[17*3/15]

E.

***EDITED****
Must have been high on something... Yeah reminder is 6 all the way. So, agree with the C gang!

Last edited by mbawaters on 19 May 2008, 10:57, edited 1 time in total.
Current Student
Joined: 28 Dec 2004
Posts: 3385
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 14

Kudos [?]: 241 [0], given: 2

### Show Tags

19 May 2008, 08:32
Yes i get C

N=3K+2 possible values 2, 5, 8, 11, 14, 17, 20, 24
T=5K+3 possible values 3, 8, 13, 18, 23,

1) says n-2=5K..n can be 2, 17
2+3=5/15 remainder =5
17+13=30 remiander=0
Insuff

2) T is multiple of 3..t can be 3, 18..

3+14=17/15 remainder =2.. 18+24=42/15 remainder=12..insuff

together..n=2 t=3 remainder 5... n=2, t=18 remainder 5..n=17 t=18 remainder=5..

i wonder if there is a shortcut to this..
Director
Joined: 23 Sep 2007
Posts: 790
Followers: 5

Kudos [?]: 155 [0], given: 0

### Show Tags

19 May 2008, 09:38
gmatnub wrote:
is it E?

Remainder is 6

Haha, I was on crack, I meant C.

BTW freshina, the remainder is 6 instead of 5
Manager
Joined: 10 Mar 2008
Posts: 67
Followers: 2

Kudos [?]: 28 [0], given: 0

### Show Tags

29 May 2008, 03:34
chineseburned wrote:
When positive integer n is divided by 3 the remainder is 2; and when positive integer t is divided by 5 the remainder is 3. What is the remainder when the product tn is divided by 15?

1) n-2 is divisible by 5
2) t is divisible by 3

Hi,

n=3x+2-----------(1)
t=5y+3-----------(2)

Statement 1:
arranging (1)
n-2=3x this means 3x is divisible by 5 let 3x=3*5*a=15a
equation (1) is now n=15a+2
not suff

Statement 2:
(2)is divisible by 3 means 5y is divisible by 3
so let 5y=3*5*b=15b

eq (2) now is t=15b+3
not suff

combining
nt=15a+2*15b+3

all terms except 6 is divisible by 6 so remainder is 6
Manager
Joined: 27 May 2008
Posts: 143
Followers: 1

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

### Show Tags

29 May 2008, 04:53
C has to be the answer.

Without look at the hints the possible values for:
n= 2,5,8,11,14,17,20,23...................
t=3,8,13,18,23...................

From hint 1

possible values of n= 17,32,47.....
t= 3,8, 13, 18

17X3/15= 6 (as rdr.)
17X8/15= 1 (rdr.)

Thus insuff.

From Hint 2

Possible values of t= 3,18,33.......
n=2,5,8,11,14,17,20,23.....
thus
18X5/15=0 (rdr)
18X11=198/15= 3 (rdr)
Thus insuff.

Combing Hint 1 and Hint 2
Possible value of n=17,32,47.....
Possible value of t= 3,18,33......

any two combos wud give 6 as a rdr

thus C.
Re: GMATPrep DS   [#permalink] 29 May 2008, 04:53
Display posts from previous: Sort by