1道数学题

real_arsen_acUID: 2413853

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 and 285/11.5
c. 285/12 and 195/12
d. 285/12.5 and 295/11.5
e. 295/12.5 and 285/11.5

答案是d. 285/12.5 and 295/11.5

请问题中的 rounded to the nearest 10 miles 和 rounded to the nearest gallon 分别是表示多少范围？
谢谢！

yawnUID: 2115183

按四舍五入的话，应该是：
285-294
11.5-12.4
不过从答案看，似乎是：
285-295
11.5-12.5