2012 AMC10A 真题

2012 AMC 10A

Problem 1

Cagney can frost a cupcake every seconds and Lacey can frost a cupcake every seconds. Working together, how many cupcakes can they frost in minutes?

Cagney 每 20 秒可以给一个蛋糕上霜， Lacey 每 30 秒可以给一个蛋糕上霜，他俩合作 5 分钟 内可以给多少个蛋糕上霜？

(A) 10 (B) 15 (C) 20 (D) 25 (E) 30

Problem 2

A square with side length is cut in half, creating two congruent rectangles. What are the dimensions of one of these rectangles?

一个边长为 8 的正方形被分成两半，得到两个全等的矩形。问其中一个矩形的尺寸是多少 ?

(A) 2 by 4 (B) 2 by 6 (C) 2 by 8 (D) 4 by 4 (E) 4 by 8

Problem 3

A bug crawls along a number line, starting at . It crawls to , then turns around and crawls to . How many units does the bug crawl altogether?

一个虫子从－ 这个点开始沿着数轴爬行。它先爬到－ ，然后掉头再爬到 。那么这只虫子 2 6 5 总共爬了多长 ?

(A) 9 (B) 11 (C) 13 (D) 14 (E) 15

Problem 4

= = Let and . What is the smallest possible degree measure for angle ?

= = 令 ， 。问角 CBD 最少是多少度？

(A) 0 (B) 2 (C) 4 (D) 6 (E) 12