问题
单项选择题
A car traveled 462 miles per tankful of gasoline on the highway and 336 miles per tankful of gasoline in the city. If the car traveled 6 fewer miles per gallon in the city than on the highway, how many miles per gallon did the car travel in the city ？（）
A．14
B．16
C．21
D．22
E．27
答案
参考答案：B
解析：
设每加仑汽油可使该汽车在城市内行驶x英里，根据题意可得到如下方程：
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