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If n is an integer, is n/15 an integer?
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29 Nov 2011, 20:02
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If n is an integer, is n/15 an integer? (1) 3n/15 is an integer. (2) 8n/15 is an integer
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Re: If n is an integer, is n/15 an integer?
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30 Nov 2011, 01:37
1. 3n/15 = n/5 We know that n is divisible by 5 . Therefore, one of n's prime factors is 5. We do not know whether or not n is also divisible by 3. Insufficient 2. 8n/15 = is also an integer For 8n/15 to be an integer, n must be divisible by 15. Sufficient B.
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Re: If n is an integer, is n/15 an integer?
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30 Nov 2011, 13:10
I know i got it wrong but can someone please tell me what is wrong with this approach? Stat 1) 3n/15 is an integer. => 3*(n/15) is an integer. Wont this be only possible if n/15 is an integer?
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Re: If n is an integer, is n/15 an integer?
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30 Nov 2011, 13:12
iamgame wrote: I know i got it wrong but can someone please tell me what is wrong with this approach?
Stat 1) 3n/15 is an integer. => 3*(n/15) is an integer. Wont this be only possible if n/15 is an integer? Ah. I correct myself...this is also possible for n=5. in that case n/15 is not an integer, given 3n/15 is an integer.
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Re: If n is an integer, is n/15 an integer?
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12 Dec 2011, 13:47
B
stmt1 : 3n/15 is an integer. the multiples of 15 are 3 and 5 and we are given a 3 in 3n. so we know that n at least has a multiple of 5 but we do not know if it contains a multiple of 3. insuff
stmt 2: 8n/15 is an integer. Using the same logic above we need a 3 and a 5. 8 is 2^3 do we know that n has the multiples of 3 and 5 so suff



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Re: If n is an integer, is n/15 an integer?
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13 Dec 2011, 17:36
I agree with B. Question rephrased as is n divisible by 3 and 5? (1) 3n/15 is integer. Tells us n is divisible by 5 but is insufficient to tell us if n is divisible by 3. INSUFF. (2) 8n/15 is integer. This is only possible if n is multiple of 15 as 8 does not have any prime factors same as 15. SUFF.
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If n is an integers, is n/15 an integer?
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Updated on: 18 Jun 2017, 02:30
If n is an integers, is n/15 an integer?
(1) 3n/15 is an integer. (2) 8n/15 is an integer
Originally posted by Prashanth3007 on 17 Jun 2017, 20:25.
Last edited by Bunuel on 18 Jun 2017, 02:30, edited 1 time in total.
Renamed the topic and edited the question.



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Re: If n is an integers, is n/15 an integer?
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17 Jun 2017, 20:36
Shan30 wrote: If n is an integers, is n/15 an integer? (1) 3n/15 is an integer. (2) 8n/15 is an integer
Can anyone please explain me why B is the answer. TIA To find out is \(\frac{n}{15}\) an integer.
(1) \(\frac{3n}{15}\) is an integer
Lets take n = 5
\(\frac{3*5}{15}\) = 1  Integer.
\(\frac{n}{15} = \frac{5}{15} = \frac{1}{3}\)  (Not an integer)
Lets take n = 15
\(\frac{3*15}{15} = 3\)
\(\frac{n}{15} = \frac{15}{15} = 1\)  (Integer)
I has multiple values therefore I is Not Sufficient.
(2) \(\frac{8n}{15}\) is an integer
Given \(\frac{8n}{15}\) is an integer.
Factors of 8 are 1,2,4,8.
15 is not a factor of 8. Hence 15 has to be a factor of n.
Therefore \(\frac{n}{15}\) is an integer.  (II is Sufficient)Answer (B)...
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Re: If n is an integer, is n/15 an integer?
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18 Jun 2017, 02:33



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Re: If n is an integer, is n/15 an integer?
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