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题库 / Prep2007E1-DS-3
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 ~$n^2$~.
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
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(1) 如果2n=2.3.5.7的話
n的prime factor為3.5.7=>三個
如果2n=2^2.3.5.7的話
n的prime factor為2.3.5.7=>四個 ,不充分
谢谢
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