2020 AMC12A 真题

2020 AMC 12A

Problem 1

Carlos took of a whole pie. Maria took one third of the remainder. What portion of the whole pie was left?

Carlos 拿走了馅饼的 70 ％， Maria 拿走了剩下的三分之一。问最后剩下原来馅饼的百分之多 少？

(A) 10% (B) 15% (C) 20% (D) 30% (E) 35%

Problem 2

The acronym AMC is shown in the rectangular grid below with grid lines spaced unit apart. In units, what is the sum of the lengths of the line segments that form the acronym AMC

缩略词 AMC 如下显示在直角网格里，网格线之间的距离是 1 个单位。那么形成缩略词 AMC 的所有线段长度之和是多少？

Problem 3

A driver travels for hours at miles per hour, during which her car gets miles per gallon of gasoline. She is paid per mile, and her only expense is gasoline at per gallon. What is her net rate of pay, in dollars per hour, after this expense?

一位司机以 60 英里每小时的速度开了 2 小时，在此期间她的车每消耗 1 加仑的汽油可以开 30 英里。她开 1 英里的收入是 0.5 美元，并且她的唯一支出是汽油支出，为每加仑 2 美元， 在扣除掉此支出后，她的单位时间净收入是每小时多少美元？

(A) 20 (B) 22 (C) 24 (D) 25 (E) 26