[計量] 請教一題 A postive integer with ...
A positive integer with exactly two different divisors
greater than 1 must be
A) a prime
B) an even integer
C) a multiple of 3
D) the square of a prime
E) the squate of an odd integer
答案 D
可是我不懂為什麼是D,
題目的意思應該是 "一個正整數有兩個比1還大的因數,那麼這個正整數一定:"
我舉 15 為例,15的因數為 1,3,5 符合題目的意思,
但 15 不是質數的平方啊,15 卻是 3 的倍數,所以
我選 C。
哪裡出錯了呢?請高手指點
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08/26 21:01, , 1F
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08/26 21:02, , 3F
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08/26 21:15, , 4F
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08/26 22:07, , 9F
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08/26 22:18, , 11F
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08/26 22:20, , 13F
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12/02 18:57, , 14F
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04/13 23:22,
5年前
, 15F
04/13 23:22, 15F