A silly solution

來源: 巡天劍客於 2010-10-25 07:20:20 [檔案] [舊帖] [給我悄悄話] 閱讀數 : (323 bytes)

回答: 生活中的數學（8）由 NaCl 於 2010-10-24 17:35:45

Let x be the number of first part. From wrong:right = 1:2, we know x = (3^m)y, m=1,2,3,..., y=1,2,3,... From x+16 wrong:right = 1:3, we know 4|(x+16), therefore, x = (3^m)(4^n)z. From x+16 <= 50, we know m=n=1, z=1 or 2. ==> x=12 or 24. ==> these 16 wrong:right = 3:13 or 2:14, left=22 or 10.