prime number

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prime number

by billyr » Sun Feb 22, 2009 11:38 am
If p is a prime number greater than 2, what is the value of p?

(1) there are a total of 100 prime number between 1 and p+1

(2)there are a total of p prime number between 1 and 3912



The answer is D(both statement sufficient), but i lost how to evaluate each statement/totally confused.


Thanks
Source: — Data Sufficiency |

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by cramya » Sun Feb 22, 2009 12:31 pm
I am not sure if u want to evaluate this one as it will be a time consuming calculation. Answerig it from a theoritical or analytical standpoint would be a good option. Just my opinion.

Start with the easier of the 2 statments

Stmt II
there are a total of p prime number between 1 and 3912

If u were to find this one u know u can get to P

SUFF (this data is sufficient to answer the question)

Stmt I

There are a total of 100 prime number between 1 and p+1.

For example take p = 3

There are 2 primes between 1 and p+1 (3+1) i.e 1 and 4
p=5 3 primes between 1 and p+1(6)


As u can see the number of primes increases when p value changes so there can only be 1 P value which is determinable with 100 primes between 1 and P+1

SUFF


Choose D


Regards,
CR

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Re: prime number

by x2suresh » Mon Feb 23, 2009 8:06 pm
billyr wrote:If p is a prime number greater than 2, what is the value of p?

(1) there are a total of 100 prime number between 1 and p+1

(2)there are a total of p prime number between 1 and 3912



The answer is D(both statement sufficient), but i lost how to evaluate each statement/totally confused.


Thanks
If you try to evaluate.. it may take 1 hour or so..
It is just testing.. whether you know the logic.

Definitely we can find no of prime numbers in that range..

So answer should be D.


This kind of problem will not appear in Problem Solving section.. If it appears :lol: ... :lol: