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Cramya DS 3 (M,N DIVISIBILITY)

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Cramya DS 3 (M,N DIVISIBILITY)

by cramya » Tue Dec 23, 2008 7:37 pm
If M is divisible by N, where M and N are positive integers and indivisible by 6, is M/N odd?
(1) N is divisible by 3.
(2) M is divisible by 3


OA : D

Please give detailed explanations if possible so that it helps everyone :-)
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by parallel_chase » Tue Dec 23, 2008 9:00 pm
question stem: M = Nk + 0

M and N positive integers & Both M & N are not divisible by 6

M/N = odd ??

Statement I
N is divisible 3

this means N is not divisible by 2, hence N is odd, therefore, M is also odd.

Hence, M/N = is always odd

Statement II,

this statement is exact replica of statement I

M is divisible 3

this means M is not divisible by 2, hence M is odd, therefore, N is also odd.


Hence, Odd/odd = is always odd

D.

Hope this helps.
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by cramya » Tue Dec 23, 2008 9:04 pm
Good work PC.

One thing I would like to add is

Odd/odd = odd or decimal

9/3 or 3/9 but in the problem(M/N) like PC said it is odd integer since M is divisible by N.
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by parallel_chase » Tue Dec 23, 2008 9:06 pm
cramya wrote:Good work PC.

One thing I would like to add is

Odd/odd = odd or decimal

9/3 or 3/9 but in the problem(M/N) like PC said it is odd integer since M is divisible by N.
M can only be 9 never be 3 because M is divisible by N

Therefore, Odd/odd or M/N = odd.

Hope this helps.
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by cramya » Tue Dec 23, 2008 9:07 pm
M can only be 9 never be 3 because M is divisible by N

Therefore, Odd/odd or M/N = odd.

Hope this helps
Sorry for the confusion I meant in general odd/odd could be odd integer or decimal but in the problem above like u said its an odd integer since M is divisible by N.
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by parallel_chase » Tue Dec 23, 2008 9:09 pm
cramya wrote:
M can only be 9 never be 3 because M is divisible by N

Therefore, Odd/odd or M/N = odd.

Hope this helps
Sorry for the confusion I meant in general odd/odd could be odd integer or decimal but in the problem above it like u said its an odd integer since M is divisible by N.
Dude, I was just about to delete my post, but couldnt since you already replied.

Anyways its all good, Nothing wrong in revising the same rule 4 times in the same post :)
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by cramya » Tue Dec 23, 2008 9:10 pm
Nothing wrong in revising the same rule 4 times in the same post

Amen to that!!! :-)
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by vivek.kapoor83 » Tue Dec 23, 2008 9:23 pm
IF m,n is not divisble by 6 then they cant be divisble by 2. hence odd
like 15,21,27 etc

1. if N is divisble by 3. Then all the no. which are odd and divisible by odd no. 3 will yield odd Q. So, M/N odd

2.If M is divisble by 3.Here. M/N to be divisble and M is multiple of 3 ...then N has to be odd for M/N to be divisble. So ODD

Hence IMO D.
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by ronniecoleman » Tue Dec 23, 2008 9:49 pm
If M is divisible by N, where M and N are positive integers and indivisible by 6, is M/N odd?
(1) N is divisible by 3.
(2) M is divisible by 3



M = K2
N = 3K1


K2 = 3K1*K3

Since M is not divisible by 6 so, K1*K3 = ODD.

SUFF,



2) M = 3*K1
N = K2

K1 is ODD

So M/N is ODD


IMO D
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by vittalgmat » Tue Dec 23, 2008 10:30 pm
Here is my approach .. Not sure if this is correct.

Question stem says M, N are int and M divisible by N and indivisible by 6.

So indivisible by 6 => M and N could 2 or 3 as one of its factors BUT NOT BOTH.

Stmt 1:
N is divisible by 3.
=> N has 3 as one of the factors. => N does not have 2 as a factor.
So N is ODD.
But M is divisible by N. Therefore M/N is ODD
Sufficient.


Stmt 2:
M is divisible by 3. So M has 3 as one of the factors. So M does not have 2 as a factor.
Since M divisible by N, N should have 3. Therefore M/N is ODD
Sufficient.

And D
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