关于“what percent"的问题

二丫zheng

During a trip on expressway,don drove a total of x miles.His average speed on a 5 mile section is 30miles/hr and his average speed of remainder of trip was 60 miles/hr.His travel time was what percent greater than it would have been if he had traveled at constant rate of 60 miles /hr.

最后一句话不好理解啊？分母到底是什么？每次遇到这种“what percent ……”的题就找不准分子和分母了。请问大家关于此类有什么方法吗？谢谢啊

二丫zheng

分子 “His travel time ” 即前面描述的“During a trip on expressway,don drove a total of x miles.His average speed on a 5 mile section is 30miles/hr and his average speed of remainder of trip was 60 miles/hr ” 情况下的 travel time;

分母  “it would have been if he had traveled at constant rate of 60 miles /hr.“  it 当然指的是”travel time“。

-- by 会员 51xt (2011/5/2 23:48:09)

呃，好像分子不仅仅是his travel time，还要减去他在匀速60m/h时的时间……