GPREP

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by aj5105 » Wed Oct 08, 2008 2:07 am
How many different prime numbers are factors of the positive integer n?
1). four different prime numbers are factors of 2n.
2). four different prime numbers are factors of n^2.

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by sumiwali » Wed Oct 08, 2008 3:34 am
Answer B

Statement1 2n has 4 different prime factors.

2n could be 2*3*5*7(i.e. for n 3 diff prime factors) OR 2n could be 2*2*3*5*7(i.e. 4 different prime factors for 2n and 4 different prime factors for n)

Thus INSUFF

Statement 2

n^2 has 4 different prime factors i.e.(2*3*5*7)^2 thus n will always have 4 different prime factors.

thus SUFF
hence answer is B.
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