阿明饲养了24匹英国纯种马。他将正方形的马厩横竖进行了3等分,每栏放3匹马。为了防止马匹被盗,阿明每晚临睡前都要检查一遍横列和竖列是否各有9匹马。可是,一天夜里盗贼还是在阿明不知不觉中盗走了4匹马,阿明竟然过了好几天才发觉。 Amin kept 24 British thoroughbreds. He made three equal divisions of the square’s stables and three horses per column. In order to prevent the horses from being stolen, Amin had to check each row and column for nine horses each night before going to sleep. However, one night the thieves still stole four horses unconsciously in Amin, and Amin went so far as to find out.