Probability

There are white stones and black stones in the box. When you randomly take a stone out of this box, find the probability that it will be a white stone.

When you line up cards with different natural numbers, find the probability that they will be arranged in order of size.

When randomly selecting two students from junior class and senior class , find the probability that both will be senior students.

When one ball is randomly taken out of a box containing blue balls, red balls, and some white balls, the probability of a blue ball coming out is . Find the number of white balls in the box.

According to the weather forecase it will snow with a probability of tomorrow. Find the probability that it will not snow tomorrow.

If two representatives were selected from class A having students and class B having students, find a probability that at least one student was selected from class A.

When you randomly take one ball out of a box containing blue, red, and yellow balls, find the probability that the ball you take out is a blue or yellow ball.

baseball team's first and second hitters' on-base percentages are and , respectively. Find the probability that both of them get on base.

Box A contains red balls and blue balls, box B contains red balls and yellow balls. Find the probability that at least one ball is a red ball when two ball are randomly taken out each from two boxes.

Find the probability that at least one of the two will pass when the probability of Beatrice passing the certification test is and Keith passing the test is , respectively.

Box A contains yellow balls and blue balls, box B contains yellow balls and blue balls. When you randomly take one ball out of two boxes A and B, find the probability that a ball of different colors will come out of the two boxes.

When the probabilities that two natural numbers and are odd numbers are and , respectively, find the probability that is even.

When you take one ball out of a box containing yellow and red balls randomly, check the color, put it back in the box, and take one ball out again. Find the probability of a yellow ball coming out both times in this case.

There is a box which contains white and black balls. If two balls are taken out of the box one after another, what is the probability that both balls taken out are white.

If two marbles are drawn randomly from a box containing white marbles and black marbles, what is the probability of getting one white marble and one black marble each? (Note, the marbles taken out are not put back.)

The chance for Whitney to correctly solve the problem A is , and for the problem B. In this case, find the probability that she solves at least one problem correctly.

Kianna randomly checked the answers for true/false questions. What is the probability that she only get one correct?

Gemma and Noel promised to meet on Sunday. However, they have some homework left which makes them less possible to see each other. If there are probabilities of and for Gemma and Noel to get stuck in the homeworks on Sunday, find the probability for them to meet on Sunday as planned.

The probabilities that Walter and Charlie hit the clay with shotguns are and , respectively. Find the probability that the clay gets hit when they shoot together.

There are three hunters whose hit rates are , , , respectively. If they shoot a wild boar at the same time, what is the probability of the wild boar getting shot?

The probability of reading on the day after Sabrina reads is , and the probability of reading on the day after she does not read is . Find the probability that Sabrina, who read on Thursday, will not read on Saturday, two days later.