Please check my answers, if any of these is not correct, please help. Thank you very much.
Three marbles are drawn at random from an urn containing 8 black, 7 white, and 5 red marbles.
What is the probability that none of them are white. Answer: .
What is the probability that at least one of them is red? Answer:
A drawer contains 8 blue socks, 4 green socks, and 6 brown socks. If you choose 2 socks at random, what is the probability that they are both brown? Answer:
On a 10-questions true-false test, the questions are answered at random. What is the probability of answering at least 8 questions correctly? Answer:
Three letters are chosen at random from the word POSTER. What is the probability that the selection will contain E or O or both?
Please help me with this one.
Hello, Dori!
Your "marbles" and "socks" answers are correct.
This is a Binomial Probability problem . . .On a 10-questions true-false test, the questions are answered at random.
What is the probability of answering at least 8 questions correctly?
. .
And add them up . . .
From your work on the other two problems, you should have nailed this one.Three letters are chosen at random from the word POSTER.
What is the probability that the selection will contain E or O or both?
There are: . possible outcomes.
How many outcomes contain no E's or O's?
. . There are: . of them.
Therefore: .