#### 题目列表

How many positive divisors of 210 can be expressed as a product of two prime factors?
xy ≠ 0 , x > y

#### Quantity A

$\frac{1}{x}$

#### Quantity B

$\frac{1}{y}$

a ≠ 0

a+1

#### Quantity B

$\frac{1}{a}$ - 1

-1 < x < 1

|1-x|

1

#### Quantity A

The number of positive even integers less than 100, each of which is the square of an integer

#### Quantity B

The number of positive odd integers less than 100, each of which is the square of an integer

There are two parallel lines, and the third line intersects these two lines.

#### Quantity A

The number of points with equal distance from three lines

#### Quantity B

3

Two sides of an isosceles triangle have lengths 5 and 5.

#### Quantity A

The perimeter of the triangle

#### Quantity B

15

The different committees consist of 8, 10 and 13 people, respectively. If N is the total number of different people in the 3 committees combined, what is the least possible value of N?
Eight students of different heights need to be arranged into two rows of seats. Each row has four seats. For each column, the student in the row ahead needs to be shorter than the student in the row behind. In how many ways can these students be arranged?
An urn contains 4 red balls, 8 green balls and 2 yellow balls. Five balls are randomly selected WITH replacement from the urn. What is the probability that 1 red ball, 2 green balls, and 2 yellow balls will be selected?

An eight-digit integer is formed by three "1" and five "2". How many different such integers can be formed?
Event A and event B are independent event. If the probability that even A occurs is 0.4 and event B occurs is 0.3, what will be the probability that at least one event occurs?

In an equilateral triangle ABC,three points P,Q and R are on the side AB,AC and BC, respectively.

#### Quantity A

The sum of any two interior angles in Δ ABC

#### Quantity B

The sum of any two interior angles in Δ PQR

a

b

x

#### Quantity B

90

△ABC is an isosceles triangle, BA=BC, DE is parallel to AC. If the perimeter of both triangle BDE and quadrilateral ADEC equals to 18 (the length of all the sides are integers), then what is the length of DE?
n is the number of three-digit positive integers in which at least two of the digits are equal to 1.

n

#### Quantity B

29

A committee of 4 people consisting of 2 men and 2 women is to be selected from 5 sets of fraternal twins, where each set consists of one man and one woman. If only 1 person from each set of twins may be selected for the committee, what is the total number of distinct committees that can be formed?
How many integers between 100 and 1,000 are multiples of 7?

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