23) Is N a factor of 24?
(1) 48 is a factor of 3n
(2) 60 is a factor of 5n
My Solution :
Rephrase : do factors contain 2*2*2*3
(1) Gives 2*2*2*2 hence insuff
(2) Gives 2*2*3 hence insuff
I feel the answer is C but it's given as B? What are your views?
Is N a factor of 24?
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- riteshbindal
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A --> 48 is a factor of 3n => 16 is a factor of n. So n can be 1, 2, 4, 8 and 16. Now all these values are factors of 24 except 16 so Insuff.varunkh85 wrote:23) Is N a factor of 24?
(1) 48 is a factor of 3n
(2) 60 is a factor of 5n
My Solution :
Rephrase : do factors contain 2*2*2*3
(1) Gives 2*2*2*2 hence insuff
(2) Gives 2*2*3 hence insuff
I feel the answer is C but it's given as B? What are your views?
B --> 60 is a factor of 5n => 12 is a factor of n. So n can be 1, 2, 3, 4, 6 and 12. All of these are factors of 24 so this is sufficient to say that N is a factor of 24. Hence B is the answer
- Turnpike
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okay,
(1) 48 is a factor of 3n
that means that the least value of 3n would be 48.
you know, 3n/48 = 48/48 = 1.
if that is so then solving 3n = 48 gives me: n= 16.
but 16 is not a factor of 24,
so go to (2):
if 60 is a factor of 5n, then the least value of 5n would be 60.
again, 5n/60 = 60/60 = 1 if 5n = 60
solving for n gives us n = 12,
so yep, 12 is a factor of 24.
However, if in (2) we take 5n = 180, then 60 is a factor of 5n. but then n becomes 180/5 = 36, but 36 is NOT a factor of 24!!!
y'know, for n to be a factor of 24, it must have a maximum value of 24. i can give you n = 24 if i take 5n = 120
so with (2) only 2 values of n will suit us - 12 and 24. but like is showed, there are other possible values of n as well.
combining (1) & (2) is not helping me either. so, i'll go with 'E'
please correct me if my approach is wrong.
(1) 48 is a factor of 3n
that means that the least value of 3n would be 48.
you know, 3n/48 = 48/48 = 1.
if that is so then solving 3n = 48 gives me: n= 16.
but 16 is not a factor of 24,
so go to (2):
if 60 is a factor of 5n, then the least value of 5n would be 60.
again, 5n/60 = 60/60 = 1 if 5n = 60
solving for n gives us n = 12,
so yep, 12 is a factor of 24.
However, if in (2) we take 5n = 180, then 60 is a factor of 5n. but then n becomes 180/5 = 36, but 36 is NOT a factor of 24!!!
y'know, for n to be a factor of 24, it must have a maximum value of 24. i can give you n = 24 if i take 5n = 120
so with (2) only 2 values of n will suit us - 12 and 24. but like is showed, there are other possible values of n as well.
combining (1) & (2) is not helping me either. so, i'll go with 'E'
please correct me if my approach is wrong.
Last edited by Turnpike on Sun Aug 09, 2009 4:41 am, edited 1 time in total.
- Turnpike
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i'm just curious:riteshbindal wrote:A --> 48 is a factor of 3n => 16 is a factor of n. So n can be 1, 2, 4, 8 and 16. Now all these values are factors of 24 except 16 so Insuff.varunkh85 wrote:23) Is N a factor of 24?
(1) 48 is a factor of 3n
(2) 60 is a factor of 5n
My Solution :
Rephrase : do factors contain 2*2*2*3
(1) Gives 2*2*2*2 hence insuff
(2) Gives 2*2*3 hence insuff
I feel the answer is C but it's given as B? What are your views?
B --> 60 is a factor of 5n => 12 is a factor of n. So n can be 1, 2, 3, 4, 6 and 12. All of these are factors of 24 so this is sufficient to say that N is a factor of 24. Hence B is the answer
if we look at (2) which says 60 is a factor of n,
and then you said n = 1,2,3,4,5,6,12;
if, say n = 1, then 5n = 5.
then how will (2) hold that says 60 is a factor of 5n.
it become that 60 is a factor of 5?
i didn't quite get it.
varunkh85 wrote:23) Is N a factor of 24?
(1) 48 is a factor of 3n
(2) 60 is a factor of 5n
My Solution :
Rephrase : do factors contain 2*2*2*3
(1) Gives 2*2*2*2 hence insuff
(2) Gives 2*2*3 hence insuff
I feel the answer is C but it's given as B? What are your views?
i feel C should be answer.
from each statement nothing can be told but both statements together say that n is multiple of 48. hence not a factor of 24
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Question rephrase:Is N of the form 2^3*3k
1. 48 is a factor of 3N => 2^4*3 is a factor of 3N.Hence N is of the form 2^4*k1
2. 60 is a factor of 5N hence N is of the form 2^2*3.
From 1 and 2 N is def of the form 2^4*3.Hence suff.
C is the answer.
1. 48 is a factor of 3N => 2^4*3 is a factor of 3N.Hence N is of the form 2^4*k1
2. 60 is a factor of 5N hence N is of the form 2^2*3.
From 1 and 2 N is def of the form 2^4*3.Hence suff.
C is the answer.
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guys,varunkh85 wrote:23) Is N a factor of 24?
(1) 48 is a factor of 3n
(2) 60 is a factor of 5n
My Solution :
Rephrase : do factors contain 2*2*2*3
(1) Gives 2*2*2*2 hence insuff
(2) Gives 2*2*3 hence insuff
I feel the answer is C but it's given as B? What are your views?
I am lost here..plz help and correct me, because this is fundamental issue I am not getting.
question asks if n is a factor of 24?
The restate: is N equal to 1, 2, 3, 4, 6, 8, 12, or 24?
So we are looking to see if based on statements if N equals these possibilities. This is a yes/no data sufficiency problem. Therefore if I can definitively answer NO or YES based on the statements given, the data is sufficient.
Statement 1)
48 is a factor of 3n translates to 16 is a factor of n. This means at the very least n is 2^4 or 16. 16 is not one of the possibilities in the restate. Moreso, if N comprises of an additional prime(on top of 2^4) we don't know about such as 3 , 5, 7 etc. N would definitely not be a factor of 24. We definitively know N is not a factor of 24, so isn't this sufficient??
Statement 2)
60 is a factor of 5n translates to 12 is a factor of n. This means at the very least n is 2^2 x 3 or 12. Now there is a 12 in the possibilities of factors for N. However, if N comprises of an additional prime(on top of 2^2 x 3) we don't know about such as , 5, 7 etc. N would not be a factor of 24 if it was 2^2 x 3 x 7 or 84. So insufficient, N could be a factor of 24 or not.
Why not A?
Thanks.
Factors of 60 are 12, 6,4,3,2,1
To find out if n is one among them
St 1 - (1) 48 is a factor of 3n...in this case n could be 1,2 or 4 insufficient as rest of factors are not divisors of 48.
(2) 60 is a factor of 5n...again n could be 1,2,4 or 6..insuficient
Combining both......still insufficient.
I would go with E.
GID09
To find out if n is one among them
St 1 - (1) 48 is a factor of 3n...in this case n could be 1,2 or 4 insufficient as rest of factors are not divisors of 48.
(2) 60 is a factor of 5n...again n could be 1,2,4 or 6..insuficient
Combining both......still insufficient.
I would go with E.
GID09
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answer should be C
From 1 we get N/16 is an integer - insufficient
From 2 we get N/12 is an integer - insufficient
From 1 and 2 we get that N/12 and N/16 are integers. therefore N has to be minimum of 48 i.e. LCM of 12 and 16 to be integer.
Hence C.
From 1 we get N/16 is an integer - insufficient
From 2 we get N/12 is an integer - insufficient
From 1 and 2 we get that N/12 and N/16 are integers. therefore N has to be minimum of 48 i.e. LCM of 12 and 16 to be integer.
Hence C.
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IMO A
1)48K=3N
N=16K
N=16,32,..
Definitely not a factor of 24.
SUFF
2)60K=5N
N=12K
N=12,24,36..not suff
or am i missing something here??
1)48K=3N
N=16K
N=16,32,..
Definitely not a factor of 24.
SUFF
2)60K=5N
N=12K
N=12,24,36..not suff
or am i missing something here??
The powers of two are bloody impolite!!
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3N is a multiple of 48
=> 3N could be 48, 96, 144, 192 ...
=> N could be 16, 32, 48, etc.
Hence 24 cannot be a multiple of N. In other words, N cannot be a factor of 24.
Hence A.
=> 3N could be 48, 96, 144, 192 ...
=> N could be 16, 32, 48, etc.
Hence 24 cannot be a multiple of N. In other words, N cannot be a factor of 24.
Hence A.
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Hi, people, this is my opinion:varunkh85 wrote:23) Is N a factor of 24?
(1) 48 is a factor of 3n
(2) 60 is a factor of 5n
My Solution :
Rephrase : do factors contain 2*2*2*3
(1) Gives 2*2*2*2 hence insuff
(2) Gives 2*2*3 hence insuff
I feel the answer is C but it's given as B? What are your views?
From (1) We can say this: 3n=48xK (k is a positive integer) =>
n=16xK
For N, to be a factor of 24, it's because 24=16xK, and that it is not possible: K is a positive integer!
From (2) We can say this: 5n=60xK1( K1 is a positive integer) =>
n=12xK1.
For N, to be a factor of 24, it's because 24=12xK1, and that it's possible: K1=2 (positive integer)
In that way, only from (2) we can say that N is a factor of 24. And, finally, we have to choose :
(B) if statement (2) by itself is sufficient to answer the question, but statement (1) by itself is not;
I hope this can help!
Cheers!