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Re: If n = 4p, where p is a prime number greater than 2, how many differen
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Updated on: 02 Jun 2014, 00:59
6
4
n= 4p = 2^2*p^1 so total no. of factors: (2+1)*(1+1)= 6 total no. of odd factors, since p is odd as it is a prime>2: p^1 and p^0 = 2 Total no. of even factors: 6 - 2 = 4
Now if n was n=4pq where p and q are both prime no.s greater than 2 then: total no. of factors: (2+1)*(1+1)*(1+1)= 12 total no. of odd factors, since p is odd as it is a prime>2: (1+1)*(1+1)= 4 Total no. of even factors: 12 - 4 = 8
Hi Bunuel, could you validate my logic pls?
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Originally posted by NoHalfMeasures on 01 Jun 2014, 21:06.
Last edited by NoHalfMeasures on 02 Jun 2014, 00:59, edited 1 time in total.
Re: If n = 4p, where p is a prime number greater than 2, how many differen
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20 Apr 2013, 23:04
Is one not a divisor?
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Re: If n = 4p, where p is a prime number greater than 2, how many differen
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01 Jun 2014, 23:04
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MensaNumber wrote:
n= 4p = 2^2*p^1 so total no. of factors: (2+1)*(1+1)= 6 total no. of odd factors, since p is odd as it is a prime>2: p^1 and p^0 = 2 Total no. of even factors: 6 - 2 = 4
Now if n was n=4pq where p and q are both prime no.s greater than 2 then: total no. of factors: (2+1)*(1+1)*(1+1)= 12 total no. of odd factors, since p is odd as it is a prime>2: (1+1)*(1+1)= 4 Total no. of even factors: 12 - 4 = 8
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Re: If n = 4p, where p is a prime number greater than 2, how many differen
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17 Apr 2015, 01:36
if we apply theory of finding number of divisor Let,s plug in p= 3 then n= 12 Factor of 12 are 3, 2, 2 p>2, so 2s are out Now the formula (p+1)+(q+1)+(r+1) = 3+1 = 4 Ans C
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Re: If n = 4p, where p is a prime number greater than 2, how many differen
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13 Jul 2016, 06:39
Walkabout wrote:
If n = 4p, where p is a prime number greater than 2, how many different positive even divisors does n have, including n ?
(A) Two (B) Three (C) Four (D) Six (E) Eight
This is an interesting question because we are immediately given the option to insert any prime number we wish for p. Since this is a problem-solving question, and there can only be one correct answer, we can select any value for p, as long as it is a prime number greater than 2. We always want to work with small numbers, so we should select 3 for p. Thus, we have:
n = 4 x 3
n = 12
Next we have to determine all the factors, or divisors, of P. Remember the term factor is synonymous with the term divisor.
1, 12, 6, 2, 4, 3
From this we see that we have 4 even divisors: 12, 6, 2, and 4.
If you are concerned that trying just one value of p might not substantiate the answer, try another value for p. Let’s say p = 5, so
n = 4 x 5
n = 20
The divisors of 20 are: 1, 20, 2, 10, 4, 5. Of these, 4 are even: 20, 2, 10 and 4. As we can see, again we have 4 even divisors.
No matter what the value of p, as long as it is a prime number greater than 2, n will always have 4 even divisors.
The answer is C.
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Re: If n = 4p, where p is a prime number greater than 2, how many differen
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28 Dec 2016, 07:16
One of those Quality Questions from the Official Guide. here is my solution => Method 1-> n=2^2*p as p is a odd prime (all primes >2 are odd) number of even factors => 2*2-> four Four factors are -> 2,4,2p,4p Alternatively let p=3 so n=12 factors => 1,2,3,4,6,12 even factors => 2,4,6,12 hence four
Re: If n = 4p, where p is a prime number greater than 2, how many differen
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01 Apr 2017, 06:09
n=4p Let;s factorize n n= 2^2 * p^a (a is some positive power of p and we know that p is a prime number greater than 2 i.e. it is odd as the only even prime number is 2. So we don't have to worry about the power of p as it would yield odd integer and we have to just find even factors.)
Thus the answer is 2, 4(2^2), 2p (even), and 4p (even).
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Re: If n = 4p, where p is a prime number greater than 2, how many differen
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26 Sep 2018, 21:36
Would this be an acceptable way of solving:
Prime factor the 4 that is next to p Prime factorization gives us 2^1 and 2^1 Using only Even primes with above Powers of 1, we just add 1 to the power of each and multiply - this would give us different combinations of even factors
gmatclubot
Re: If n = 4p, where p is a prime number greater than 2, how many differen &nbs
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26 Sep 2018, 21:36
close
57% (01:07) correct 
