2015 AMC12A 真题

Problem 1

What is the value of

Problem 2

Two of the three sides of a triangle are 20 and 15. Which of the following numbers is not a possible perimeter of the triangle?

一个三角形的其中两条边长度是 20 和 15 ，下面哪个数字不可能成为三角形的周长 ?

Problem 3

Mr. Patrick teaches math to 15 students. He was grading tests and found that when he graded everyone's test except Payton's, the average grade for the class was 80. After he graded Payton's test, the class average became 81. What was Payton's score on the test?

Patrick 先生给 15 个学生上数学课，他正批改考试试卷，发现当他把除了 Payton 外的所有其 他学生的试卷都改好后，班级的平均分是 80 ，当他批改好 Payton 的试试卷后，班级的平均分 变成了 81 分，问 Payton 这次考试得分是多少 ?

Problem 4

The sum of two positive numbers is 5 times their difference. What is the ratio of the larger number to the smaller?

两个正数之和是它们之差的 倍，那么大的数比小的数的比值是多少？ 5

2015 AMC12A