问一道GMAT数学题

题目

问一道GMAT数学题
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 pergallon that cindy's car got on this trip must have been between.
285/12.5 and 295/11.5
整个题目都看不懂,

答案

rounded to nearest 四舍五入到……
比如
rounded to the nearest hundred
按百位整数四舍五入
For example,if you change a field from Double to Long Integer,decimal numbers are rounded to the nearest whole number.
例如,如果将字段从“双精度”更改为“长整型”,小数位将会四舍五入为最接近的整数.
...rounded down to the nearest HK$1,000.
...退位至最近的1000港元.