[計量] 一題數學
How many 3-digit integers can be chosen such that none of the digits appear more than twice, and none of the digits equal to zero?
我算9*8*7=504。 但答案是720
幫忙解惑
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02/09 01:44, , 1F
02/09 01:44, 1F
推
02/09 02:33, , 2F
02/09 02:33, 2F
推
02/13 23:08, , 3F
02/13 23:08, 3F
推
02/15 17:53, , 4F
02/15 17:53, 4F
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