If points A and B are randomly placed on the circumference of a circle with radius 2, what is the probability that the length of chord AB is greater than 2?

p is the probability that event E will occur, and s is the probability that event E will not occur.
Quantity A: p+s
Quantity B: ps

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: 2/3 P(A)
Quantity B: P(B or C)

In a box of 5 red socks, 4 blue socks and 3 yellow socks, someone selects a sock first, puts it back and then selects another sock. What is the probability that he or she selects yellow socks for both time?
Give your answer as a fraction.

In box H, there are 5 red balls, 3 green balls and 2 yellow balls, while In box R, there are 3 red balls and 7 yellow balls. If someone selects one ball from each box, what is the probability that he or she selects at least one yellow ball?

What is the probability that the selected number are the same when selecting one letter from each of the word JOHNONS and JONES?
Give your answer as a fraction.

Set A: {71,73,79,83,87}
Set B: {57,59,61,67}
If one number is selected at random from set A, and one number is selected at random from set B, what is the probability that both numbers are prime?

20 boys and 40 girls are in Group A, while at least 7 boys, together with some girls are in Group B. To choose one person from each of the group, the probability that both are boys is no greater than 1/15. Which of the following statements must be true?
Indicate all such statements.

A and B are independent events, and the probability that both events occur is 1/2. Which of the following could be the probability that event A occurs?
Indicate all such probabilities.

Events A and B are independent.
The probability that events A and B both occur is 0.6
Quantity A: The probability that event A occurs
Quantity B: 0.3

A box contains 10 balls numbered from 1 to 10 inclusive. If Ann removes a ball at random and replaces it, and then Jane removes a ball at random, what is the probability that both women removed the same ball?

In a probability experiment, G and H are independent events. The probability that G will occur is r, and the probability that H will occur is s, where both r and s are greater than 0.
Quantity A: The probability that either G will occur or H will occur, but not both
Quantity B: r+sr*s

The probability that one can get through on any of the n telephone lines is 0.7 (each telephone line is separate). At least how many telephone lines do you need to ensure that the probability you can get through reach over 0.99?

What is the probability of selecting different colors when selecting 2 balls out of a box of 10 red balls and 6 blue balls without replacement?
Give your answer as a fraction.

In a box of 10 balls, 4 are red while 6 are blue. What is the probability that all the 3 balls are red when randomly selecting 3 balls out of the box without replacement?
Give your answer as a fraction.

There are only similar number of red and green balls in a box. A person first randomly selects a ball from the box without replacement, and continues to select another ball. Which of the following probability is 1/2?
Indicate all that are true.

The probability that a component fails during first use is 0.1. If the component doesn`t fail during first use, then the probability that the component won`t fail in the following six months is 0.8
Quantity A: The probability that the component won`t fail within six months
Quantity B: 0.75

Among 5 different red envelopes, 2 include cash, 3 include gifts. If you choose two red envelopes without replacement, what is the probability that cash is selected at least once?
Give your answer as a fraction.

In a box, the probability that the red ball is selected is 5/8. Mark randomly selects balls twice from the box without replacement. If he didn`t get a red ball in the first attempt, then the probability that he gets a red ball in the second attempt is 2/3. What is the probability that Mark get at least one red ball?
Give your answer as a fraction.

In a box, the probability that the red ball is selected is 5/8. Mark randomly selects balls twice from the box without replacement. If he didn`t get a red ball in the first attempt, then the probability that he gets a red ball in the second attempt is 2/3. What is the probability that Mark gets one red ball either in the first attempt, or in the second attempt, but not both?
Give your answer as a fraction.
