#### 题目列表

4 out of 10 students have a certain feature. When selecting 3 out of these 10 students to form a committee, what is the probability that at least two selected students have such feature?
If someone selects one letter from JOHNONS and one letter from JONES,what is the probability that the two letters selected are the same?
Three typists work for four companies,each company has one document,what is the probability that three typists all receive documents?
Among Event A, Event B and Event C, Event B and Event C are mutually exclusive, 0 < P(A) < 1, P(A)=2P(B)=3P(C)

#### Quantity A

$\frac{2}{3}$

#### Quantity B

P(B or C)

There five red socks, four blue socks and three yellow socks in the box. They are same except for color. Randomly take one from the box, and then put it back and randomly take another one. What is the probability that both socks are yellow?
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?
If it takes P and S together 1 hour and 20 minutes to fill $\frac{2}{3}$ of a swimming pool, and another 50 minutes for S alone to fill the rest, how many hours will it take if P is supposed to fill the entire swimming pool alone?
If 125w + 25x + 5y + z = 264, and w, x, y and z are integers no less than 0 and no greater than 5, then the sum of w, x, y and z could be? Indicate all such values

The circle in the xy-plane shown has radius 5 and center O. Line l has a slope of $\frac{1}{2}$ and passes through the center of the circle. P is the point in the first quadrant at which l intersects the circle. Which of the following represents the coordinates of point P?

△MNO is inscribed in semicircle MNO with radius r.

#### Quantity A

$x^{2}$+$y^{2}$

#### Quantity B

4$r^{2}$

AB

#### Quantity B

BC

As a result of a chemical reaction between compounds A and B. $\frac{1}{4}$ of each compound was transformed into an equal amount of the other compound, while the remaining $\frac{3}{4}$ of each compound was not transformed. If the amount of B was initially 4 times the amount of A. what was the ratio of the amount of A to the amount of B after the reaction?
All the chairs in a certain cargo have the same weight, and all the tables in the cargo have the same weight. There are 6 times as many chairs as there are tables. The weight of each table is 9 times the weight of each chair. If the total weight of the tables is 1,200 kilograms, then the total combined weight of the chairs and tables is how many kilograms?

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