2007 AMC 10B 第 6 题

Question

2007

年 AMC

10

的计分规则为：每答对一题得

6

分，每答错一题得

0

分，每道未答题得

1.5

分。Sarah 看完

25

道题后决定尝试前

22

题，只留下最后

3

题不答。为了至少得到

100

分，她前

22

题中至少要答对多少题？

The

2007

AMC

10

will be scored by awarding

6

points for each correct response,

0

points for each incorrect response, and

1.5

points for each problem left unanswered. After looking over the

25

problems, Sarah has decided to attempt the first

22

and leave only the last

3

unanswered. How many of the first

22

problems must she solve correctly in order to score at least

100

points?

13

14

15

16

17

答案：D

知识点：不等式一次方程

难度评级：1120

小提示：

未答题也会贡献分数。

The unanswered problems still contribute points

大提示：

先减去

3

道空题的分数，再用剩下需要的分数除以

6

。

Subtract the points from the

3

blanks, then divide the remaining needed points by

6

解答：

三道空题给

3\cdot 1.5 = 4.5

分，所以 Sarah 需要从前

22

题得到

100-4.5=95.5

分。

因为

\frac{95.5}{6}

介于

15

和

16

之间，她至少要答对

16

题，此时总分为

100.5

。

所以正确答案是 D。

The three blank problems give

3\cdot 1.5 = 4.5

points, so Sarah needs

100-4.5=95.5

points from the first

22.

Since

\frac{95.5}{6}

lies between

15

and

16,

she must answer at least

16

correctly, which would give a score of

100.5.

Thus, the correct answer is D.

2007 AMC 10B 第 6 题

答案：D

难度评级：1120

小提示：

大提示：

解答：

其他年份的第 6 题