If n divided by 7 has a remainder of 2, what is the remainder when 3

Question

If n divided by 7 has a remainder of 2, what is the remainder when 3 times n is divided by 7?

A. 1
B. 2
C. 3
D. 5
E. 6

stonecold · Accepted Answer

As per question => N=7P+2 for some integer p
hence 3N => 21Q + 6 => remainder => 6 for some integer Q
Alternatively => N=2 > 3N=> 6 => 6 divided by 7 will leave a remainder 6
hence E
I hope it helps.
Peace Out ..
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bethebest · Answer

Is it ok to multiply the entire equation by 3, like you did. I plugged in the values and got the right answer because was not sure of the multiplication approach. Can this be used a s a rule?

stonecold · Answer

It is completely Fine to multiply the equation by any integer as long as it is not zero.
here since it is a P.S question you can plug in the values to.
However by using the basic mathematical logic => it can be done in a few seconds.
Now your approach is absolutely fine ; Although i would recommend using the above technique so that you become more familiar with the concept of remainders.
During the exam =>Use the approach that you feel is the easiest .
Feel free to ask any more Questions
Peace Out 
S.C.S.A

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bethebest · Answer

N=7P+2, Multiply by 3 -> 3N = 21Q + 6
Is this correct? I ask because you put & instead of 21. not sure if that is a typo? 
Thanks

stonecold · Answer

exactly MeghaP that was a typo

Regards S.C.S.A

srinidhi mishra · Answer

What is the level of these question ?

Abhishek009 · Answer

Least possible value of n = 2
 
Thus, the remainder will be 6
  
Hence, answer will be (E) 6

gracie · Answer

let n=2
if 2/7 gives a remainder of 2,
then (2*3)/7 gives a remainder of 6
E

EMPOWERgmatRichC · Answer

Hi All,

We're told that when N is divided by 7, the remainder is 2. We're asked for the remainder when 3N is divided by 7. This question can be solved rather easily by TESTing VALUES.

N can actually be lots of different values, so I'll list out the first several: N/7 = __ r 2...... N = 2, 9, 16, 23, 30, etc.

IF.... N=9... 
3(9)/7 = 27/7 = 3 r 6

So the remainder is 6.

Final Answer:  E

GMAT assassins aren't born, they're made, 
Rich

BrentGMATPrepNow · Answer

----ASIDE-------------------------
When it comes to remainders, we have a nice rule that says: 
  If N divided by D leaves remainder R, then the possible values of N are R, R+D, R+2D, R+3D,. . . etc.    
For example, if k divided by 5 leaves a remainder of 1, then the possible values of k are: 1, 1+5, 1+(2)(5), 1+(3)(5), 1+(4)(5), . . . etc. 
-----------------------------

In this case we are told that n divided by 7 leaves a remainder of 2
So the possible values of n are: 2, 9, 16, 23, etc....

So let's say n equals  2 
The question becomes "What is the remainder when 3 times  2  is divided by 7?"
In other words, "What is the remainder when 6 is divided by 7?"
7 divides into 6 zero times, leaving a remainder of 6

Answer: E

Cheers, 
Brent

RELATED VIDEO
 https://www.youtube.com/watch?v=XCxgIR042tE

Kinshook · Answer

n= 7x+2
3n = 21x + 6

IMO E

Posted from my mobile device

ScottTargetTestPrep · Answer

We can let n = 2. Thus:

(3 x 2)/7 = 6/7 = 0 remainder 6.

Answer: E

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If n divided by 7 has a remainder of 2, what is the remainder when 3

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If n divided by 7 has a remainder of 2, what is the remainder when 3

Prep Toolkit

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