2012 AMC12B 真题

2012 AMC12B

Problem 1

Each third-grade classroom at Pearl Creek Elementary has 18 students and 2 pet rabbits. How many more students than rabbits are there in all 4 of the third-grade classrooms?

Pearl Creek 小学的每一个三年级教室都有 18 个学生和 只宠物兔，问四个三年级教室的学生 2 总数比宠物兔总数多出多少个 ?

(A) 48 (B) 56 (C) 64 (D) 72 (E) 80

Problem 2

A circle of radius 5 is inscribed in a rectangle as shown. The ratio of the length of the rectangle to its width is 2:1. What is the area of the rectangle?

如图所示，一个半径为 的圆和一个矩形内切，矩形的长和宽之比为 5 2:1 ，问矩形的面积是多 少 ?

Problem 3

For a science project, Sammy observed a chipmunk and squirrel stashing acorns in holes. The chipmunk hid 3 acorns in each of the holes it dug. The squirrel hid 4 acorns in each of the holes it dug. They each hid the same number of acorns, although the squirrel needed 4 fewer holes. How many acorns did the chipmunk hide?

为了完成一项科学作业， Sammy 观察花栗鼠和松鼠在洞里藏橡果的情况。花栗鼠在它所挖的 每个洞里藏 颗橡果，而松鼠在它所挖的每个洞里藏 颗橡果，它们藏的橡果的总数一样 3 4 多，但是松鼠所需要的洞比花栗鼠的少 个，问花栗鼠藏了多少颗橡果 4 ?

(A) 30 (B) 36 (C) 42 (D) 48 (E) 54