Question

Patrick 先生教 $15$ 名学生数学。他批改测验时发现，在批完除 Payton 以外所有人的试卷后，全班平均分为 $80$ 。批完 Payton 的试卷后，测验平均分变为 $81$ 。Payton 的测验分数是多少？

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?

$81$

$85$

$91$

$94$

$95$

答案：E

知识点：平均数

难度评级：870

解答：

前 $14$ 份已批改试卷的总分为 $14\cdot 80=1120$ 。

加入 Payton 的试卷后，总分为 $15\cdot 81=1215$ ，所以 Payton 的分数为 $1215-1120=95$ 。

所以正确答案是 E。

The total for the first $14$ graded tests was $14\cdot 80=1120$ .

After Payton's test was included, the total became $15\cdot 81=1215$ . Therefore Payton's score was $1215-1120=95$ .

Thus, E is the correct answer.

2015 AMC 10A 第 5 题

答案：E

难度评级：870

解答：

其他年份的第 5 题