题库列表

The bar graph shows the grades in a mathematics class for the last grading period. If A, B, C, and D are satisfactory grades, what fraction of the grades shown in the graph are satisfactory?

柱状图显示了一个数学班上个评分周期的成绩。如果 A、B、C 和 D 是及格成绩，图表中显示的及格成绩占几分之几？

正确答案：C · 分值：1

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1985 AMC8 #6 · Algebra · ★★

A ream of paper containing 500 sheets is 5 cm thick. Approximately how many sheets of this type of paper would there be in a stack 7.5 cm high?

一令纸含有 500 张，厚度为 5 厘米。同类型的纸叠成 7.5 厘米高的一摞，大约有多少张？

正确答案：D · 分值：1

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1985 AMC8 #7 · Algebra · ★★

A "stair-step" figure is made of alternating black and white squares in each row. Rows 1 through 4 are shown. All rows begin and end with a white square. The number of black squares in the

37\text{th}

row is

一个"阶梯"图形由每行交替的黑白正方形组成。图中显示了第 1 行到第 4 行。每行都以一个白色正方形开始和结束。第 37 行中黑色正方形的数量是

正确答案：C · 分值：1

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1985 AMC8 #8 · Algebra · ★★

If a = - 2 , the largest number in the set

\displaystyle \{ - 3a, 4a, \frac {24}{a}, a^2, 1\}

若 a = -2，集合

\displaystyle \{-3a, 4a, \frac{24}{a}, a^2, 1\}

中最大的数是

正确答案：A · 分值：1

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1985 AMC8 #9 · Algebra · ★★

The product of the 9 factors

9 个因子之积

正确答案：A · 分值：1

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1985 AMC8 #10 · Algebra · ★★

The fraction halfway between

\displaystyle \frac{1}{5}

and

\displaystyle \frac{1}{3}

(on the number line) is

数轴上

\displaystyle \frac{1}{5}

和

\displaystyle \frac{1}{3}

正中间的分数是

正确答案：C · 分值：1

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1985 AMC8 #11 · Geometry · ★★★

A piece of paper containing six joined squares labeled as shown in the diagram is folded along the edges of the squares to form a cube. The label of the face opposite the face labeled

\text{X}

一张纸上有六个相连的正方形，标记如图所示。将纸沿正方形的边折叠形成一个正方体。与面

\text{X}

相对的面上的标记是

正确答案：E · 分值：1

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1985 AMC8 #12 · Geometry · ★★★

A square and a triangle have equal perimeters. The lengths of the three sides of the triangle are

6.2 \text cm

8.3 \text cm

and

9.5 \text cm

. The area of the square is

一个正方形和一个三角形周长相等。三角形三边长分别为

6.2 \text{ cm}

、

8.3 \text{ cm}

和

9.5 \text{ cm}

。正方形的面积是

正确答案：B · 分值：1

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1985 AMC8 #13 · Algebra · ★★★

If you walk for 45 minutes at a rate of

4 \text{ mph}

and then run for 30 minutes at a rate of

10\text{ mph}

, how many miles will you have gone at the end of one hour and 15 minutes?

如果你以

4 \text{ mph}

的速度步行 45 分钟，然后以

10\text{ mph}

的速度跑步 30 分钟，那么在一小时 15 分钟结束时你走了多少英里？

正确答案：B · 分值：1

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1985 AMC8 #14 · Algebra · ★★★

The difference between a 6.5% sales tax and a 6% sales tax on an item priced at $20 before tax is

一件标价 $20 的商品，6.5% 销售税和 6% 销售税的差额是

正确答案：B · 分值：1

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1985 AMC8 #15 · Counting, Probability & Statistics · ★★★

How many whole numbers between 100 and 400 contain the digit 2 ?

100 到 400 之间有多少个整数包含数字 2？

正确答案：C · 分值：1

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1985 AMC8 #16 · Algebra · ★★★

The ratio of boys to girls in Mr. Brown's math class is 2:3. If there are 30 students in the class, how many more girls than boys are in the class?

Mr. Brown 的数学班上男生与女生的比例是 2:3。如果班上有 30 名学生，女生比男生多多少人？

正确答案：D · 分值：1

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1985 AMC8 #17 · Algebra · ★★★

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

如果你前六次数学考试的平均分是 84，前七次数学考试的平均分是 85，那么你第七次考试的分数是

正确答案：D · 分值：1

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1985 AMC8 #18 · Number Theory · ★★★

Nine copies of a certain pamphlet cost less than $10.00 while ten copies of the same pamphlet (at the same price) cost more than $11.00. How much does one copy of this pamphlet cost?

某种小册子九份的价钱低于 $10.00，而同一小册子十份的价钱（相同单价）高于 $11.00。该小册子一份多少钱？

正确答案：E · 分值：1

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1985 AMC8 #19 · Geometry · ★★★

If the length and width of a rectangle are each increased by 10%, then the perimeter of the rectangle is increased by

如果矩形的长和宽各增加 10%，则矩形的周长增加了

正确答案：B · 分值：1

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1985 AMC8 #20 · Number Theory · ★★★

In a certain year, January had exactly four Tuesdays and four Saturdays. On what day did January 1 fall that year?

某年一月份恰好有四个星期二和四个星期六。那年的一月一日是星期几？

正确答案：C · 分值：1

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1985 AMC8 #21 · Algebra · ★★★★

Mr. Green receives a 10% raise every year. His salary after four such raises has gone up by what percent?

Mr. Green 每年获得 10% 的加薪。经过四次这样的加薪后，他的工资上涨了百分之多少？

正确答案：E · 分值：1

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1985 AMC8 #22 · Counting, Probability & Statistics · ★★★★

Assume every 7-digit whole number is a possible telephone number except those that begin with 0 or 1 . What fraction of telephone numbers begin with 9 and end with 0 ?

假设除了以 0 或 1 开头的号码外，所有七位正整数都是可能的电话号码。以 9 开头且以 0 结尾的电话号码占几分之几？

正确答案：B · 分值：1

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1985 AMC8 #23 · Algebra · ★★★★

King Middle School has 1200 students. Each student takes 5 classes a day. Each teacher teaches 4 classes. Each class has 30 students and 1 teacher. How many teachers are there at King Middle School?

King 中学有 1200 名学生。每名学生每天上 5 节课。每位教师每天教 4 节课。每节课有 30 名学生和 1 名教师。King 中学有多少名教师？

正确答案：E · 分值：1

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1985 AMC8 #24 · Counting, Probability & Statistics · ★★★★

In a magic triangle, each of the six whole numbers 10-15 is placed in one of the circles so that the sum,

S

, of the three numbers on each side of the triangle is the same. The largest possible value for

S

在一个魔力三角形中，六个整数 10-15 各放入一个圆圈，使得三角形每条边上的三个数之和

S

相同。

S

的最大可能值是

正确答案：D · 分值：1

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1985 AMC8 #25 · Counting, Probability & Statistics · ★★★★

Five cards are lying on a table as shown. Each card has a letter on one side and a whole number on the other side. Jane said, "If a vowel is on one side of any card, then an even number is on the other side." Mary showed Jane was wrong by turning over one card. Which card did Mary turn over?

如图所示，桌上放着五张卡片。每张卡片一面是字母、另一面是整数。Jane 说：「如果任何一张卡片的一面是元音字母，那么它的另一面就是偶数。」Mary 只翻开一张卡片就证明了 Jane 是错的。Mary 翻开的是哪张卡片？

正确答案：A · 分值：1

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