3月狗狗262题。。。

gmatziyu

262. 追击问题。Ann passes the border at 12:00 noon with a speed of x hours per mile. Susan passed the border at 13:00 at a speed of half 3x/2 miles per hour. How many miles will Ann have driven past the border when Ann is overtaken by Susan. 我的答案是3x，供参考

这个题也很费解。。。觉得应该提供条件比如在同一个地点出发这样。。3x是怎样算出来的呢？追击问题一直不太明白。。谢谢

arsenallyr

susan两小时追上 所以是3x