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find the number of ways arrange the letters in CACHES so that the letter C is not in the first or third position and none of the letters A , H, E, S is in its original position. 能請大大幫我解一下這題嗎 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 122.117.206.69