Chapter 3: Problem 5
An urn contains 6 white and 9 black balls. If 4 balls are to be randomly selected without replacement, what is the probability that the first 2 selected are white and the last 2 black?
/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 3: Problem 5
An urn contains 6 white and 9 black balls. If 4 balls are to be randomly selected without replacement, what is the probability that the first 2 selected are white and the last 2 black?
All the tools & learning materials you need for study success - in one app.
Get started for free
Independent trials that result in a success with probability \(p\) are successively performed until a total of \(r\) successes is obtained. Show that the probability that exactly \(n\) trials are required is $$ \left(\begin{array}{l} n-1 \\ r-1 \end{array}\right) p^{r}(1-p)^{n-r} $$ Use this result to solve the problem of the points (Example 4i). HINT. In order for it to take \(n\) trials to obtain \(r\) successes, how many successes must occur in the first \(n-1\) trials?
When \(A\) and \(B\) flip coins, the one coming closest to a given line wins 1 penny from the other. If \(A\) starts with 3 and \(B\) with 7 pennies, what is the probability that \(A\) winds up with all of the money if both players are equally skilled? What if \(A\) were a better player who won 60 percent of the time?
Suppose that you are gambling against an infinitely rich adversary and at each stage you either win or lose 1 unit with respective probabilities \(p\) and \(1-p .\) Show that the probability that you eventually go broke is $$ \begin{array}{cl} 1 & \text { if } p \leq \frac{1}{2} \\ (q / p)^{i} & \text { if } p>\frac{1}{2} \end{array} $$ where \(q=1-p\) and where \(i\) is your initial fortune.
English and American spellings are rigour and rigor, respectively. A man staying at a Parisian hotel writes this word, and a letter taken at random from his spelling is found to be a vowel. If 40 percent of the English- speaking men at the hotel are English and 60 percent are Americans, what is the probability that the writer is an Englishman?
The color of a person's eyes is determined by a single pair of genes. If they are both blue-eyed genes, then the person will have blue eyes; if they are both brown-eyed genes, then the person will. have brown eyes; and if one of them is a blue-eyed gene and the other a brown-eyed gene, then the person. will have brown eyes. (Because of the latter fact we say that the brown-eyed gene is dominant over the blue-eyed one.) A newborn child independently receives one eye gene from each of its parents and the gene it receives from a parent is equally likely to be either of the two eye genes of that parent. Suppose that Smith and both of his parents have brown eyes, but Smith's sister has blue eyes. (a) What is the probability that Smith possesses a blue-eyed gene? Suppose that Smith's wife has blue eyes. (b) What is the probability that their first child will have blue eyes? (c) If their first child has brown eyes, what is the probability that their next child will also have brown eyes?
What do you think about this solution?
We value your feedback to improve our textbook solutions.