2017 AMC12B 真题

2017 AMC12B

Problem 1

Kymbrea's comic book collection currently has comic books in it, and she is adding to her collection at the rate of comic books per month. LaShawn's collection currently has comic books in it, and he is adding to his collection at the rate of comic books per month. After how many months will LaShawn's collection have twice as many comic books as Kymbrea's?

Kymbrea 的漫画书集目前有 30 本漫画书，并且她现在还在以每个月 2 本漫画书的速度向她的 漫画书集中增添新书。 Lashawn 的漫画书集目前有 10 本漫画书，并且目前他在以每个月 6 本 漫画书的速度向他的漫画书集中增添新书。问经过多少个月 Lashawn 的漫画书是 Kymbrea 书 的 2 倍 ?

Problem 2

Real numbers , , and satify the inequalities , , and . Which of the following numbers is necessarily positive?

实数 ， ， 满足不等式 x y z ， ， ，下面哪个数字是正数 ?

Problem 3

3;; 3y Supposed that and are nonzero real numbers such that . What is the value