129. On a recent trip, Cindy drove her car 290 miles, rounded to the nearest 10 miles, and used 12 gallons of gasoline, rounded to the nearest gallon. The actual number of miles per gallon that Cindy’s car got on this trip must have been between
(A) 290/ 12. 5 and 290/11 .5 .
(B) 295/12 and285/11 .5 .
(C) 285/12 and 295/12
(D) 285/12. 5 and295/11 .5
(E)
295/12 .5 . and
285/
11. 5
关键是帮忙翻译一下题目,那个11.5是怎么出现的作者: hoteldeville 时间: 2012-12-23 10:23
lz先要明白rounded to the nearest是神马意思,这个是四舍五入的意思,四舍五入到10mile,也就是说路程最小285,最大295,gasoline同理,最小11.5,最大12.5。所以答案的范围就是最小的路程除以最大的油耗,得出左边,最大的路程除以最小的油耗,得出右边作者: dong870501 时间: 2012-12-23 17:10