求助陈向东数学题一道P240-Q36

avala

快要考了，请各位给帮忙，看看这道题怎么解，来自陈向东数学 240页36题

A square countertop has a square tile inlay in the center, leaving an untiled strip of uniform width around the tile. if the ratio of the tiled area to the untiled area is 25 to 39, which of the following could be the width, inches, of the strip?

Ⅰ. 1

Ⅱ. 3

Ⅲ. 4

AⅠonly

BⅡ only

CⅠand Ⅱ only

D Ⅰand  Ⅲ only 

EⅠ,Ⅱ, and Ⅲ

答案选E

我只能理解到：大正方形和发行瓷砖部分的比是（25＋39）：25，得到边长之比为8：5。但对“leaving an untiled strip of uniform width around the tile”不太懂，所以题目也做不下去，麻烦各位理解的帮忙，解释一下题目以及答案，非常感谢！ 

[此贴子已经被作者于2009/8/30 0:55:49编辑过]

avala

没人回，自己顶下，麻烦哪位NN帮忙下，多多感谢