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從1到9這九個數位中有放回的取三次,每次取一個= 9 * 9 * 9 = 729其中選到至少1個5,一個偶數(2、4、6、8)的次數:只選到1個5,任一偶數,數位不重複=4*4*(3*2*1)= 96只選到1個5,選到一個重複偶數=4*(3*2*1)= 24…
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