Question

Patrick 先生教 $15$ 名学生数学。他批改试卷时发现，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，全班平均分变为 $81$ 。 Payton 这次考试得了多少分？

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：1130

解答：

其他 $14$ 个分数的总和是 $14\cdot 80 = 1120$ 。全部 $15$ 个分数的总和是 $15\cdot 81 = 1215$ 。

因此 Payton 的分数是 $1215 - 1120 = 95$ 。

因此，正确答案是 E。

The sum of the $14$ other scores was $14\cdot 80 = 1120.$ The sum of all $15$ scores was $15\cdot 81 = 1215.$

Therefore Payton's score was $1215 - 1120 = 95.$

Thus, the correct answer is E.

2015 AMC 12A 第 3 题

答案：E

难度评级：1130

解答：

其他年份的第 3 题