Question

Blake 和 Jenny 各参加了四次 $100$ 分测试。Blake 四次测试平均分为 $78$ 。Jenny 第一次测试比 Blake 高 $10$ 分，第二次比他低 $10$ 分，第三次和第四次都比他高 $20$ 分。Jenny 的平均分和 Blake 的平均分相差多少？

Blake and Jenny each took four $100$ -point tests. Blake averaged $78$ on the four tests. Jenny scored $10$ points higher than Blake on the first test, $10$ points lower than him on the second test, and $20$ points higher on both the third and fourth tests. What is the difference between Jenny's average and Blake's average on these four tests?

$10$

$15$

$20$

$25$

$40$

答案：A

知识点：平均数

难度评级：900

解答：

两人四次测试的总分差为平均分差为 $40 \div 4 = 10$ 。 $10 - 10 + 20 \cdot 2 = 40.$

所以正确答案是 A。

The total point difference between the two is $10 - 10 + 20 \cdot 2 = 40.$ The average of this difference is $40 \div 4 = 10.$

Thus, A is the correct answer.

2003 AMC 8 第 7 题

答案：A

难度评级：900

解答：

其他年份的第 7 题