Question

如果你前六次数学测验的平均分是 $84$ ，前七次数学测验的平均分是 $85$ ，那么你第七次测验的分数是

If your average score on your first six mathematics tests was $84$ and your average score on your first seven mathematics tests was $85,$ then your score on the seventh test was

$86$

$88$

$90$

$91$

$92$

答案：D

知识点：平均数

难度评级：820

解答：

七次测验的平均分是 $85$ ，总分为 $7 \times 85 = 595$ ；六次测验的平均分是 $84$ ，总分为 $6 \times 84 = 504$ 。

第七次测验的分数是 $595 - 504 = 91$ 。

所以正确答案是 D。

Seven tests averaging $85$ total $7 \times 85 = 595$ points; six tests averaging $84$ total $6 \times 84 = 504$ points.

The seventh score is $595 - 504 = 91.$

Thus, the correct answer is D .

1985 AMC 8 第 17 题

答案：D

难度评级：820

解答：

其他年份的第 17 题