分数的表达法中：

One third of them are under 10 years old.

Five in eight students are under 10 years old.

Five out of eight people like you.

老师我想问的是 one third不能直接用作定语（副词）修饰名词么？

five in eight； five out of eight这种表达方式中可以直接用作副词修饰people 是否可以这么理解， 还是要将 five in eight students 看作一个整体？  如果这样的话就是 in eight students看作后置修饰成分了？

另外想问老师的是 谓语的单复数是否由基数词one/five来定？

One family in ten owns a dishwasher.

Five in eight students are under 10 years old.