Chapter 9: Problem 59
In Exercises 57 - 60, evaluate \( _nC_r \) using a graphing utility. \( _{42}C_5 \)
Short Answer
Step by step solution
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
/*! 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 9: Problem 59
In Exercises 57 - 60, evaluate \( _nC_r \) using a graphing utility. \( _{42}C_5 \)
These are the key concepts you need to understand to accurately answer the question.
All the tools & learning materials you need for study success - in one app.
Get started for free
Consider a group of people. (a) Explain why the following pattern gives the probabilities that the people have distinct birthdays. \( n = 2: \dfrac{365}{365} \cdot \dfrac{364}{365} = \dfrac{365 \cdot 364}{365^2} \) \( n = 3: \dfrac{365}{365} \cdot \dfrac{364}{365} \cdot \dfrac{363}{365} = \dfrac{365 \cdot 364 \cdot 363}{365^3} \) (b) Use the pattern in part (a) to write an expression for the probability that \( n = 4 \) people have distinct birthdays. (c) Let \( P_n \) be the probability that the \( n \) people have distinct birthdays. Verify that this probability can be obtained recursively by \( P_1 = 1 \) and \( P_n = \dfrac{365 - (n - 1)}{365} P_{n - 1} \). (d) Explain why \( Q_n = 1 - P_n \) gives the probability that at least two people in a group of \( n \) people have the same birthday. (e) Use the results of parts (c) and (d) to complete the table. (f) How many people must be in a group so that the probability of at least two of them having the same birthday is greater than \( \dfrac{1}{2} \)? Explain.
You are dealt five cards from an ordinary deck of \( 52 \) playing cards. In how many ways can you get (a) a full house and (b) a five-card combination containing two jacks and three aces? (A full house consists of three of one kind and two of another. For example, \( A-A-A-5-5 and K-K-K-10-10 \) are full houses.)
In Exercises 79 - 86, solve for \( n \). \( _{n + 2} P_3 = 6 \cdot _{n + 2}P_1 \)
In Exercises 91 - 94, prove the identity. \( _nC_n = _nC_0 \)
You and a friend agree to meet at your favorite fast - food restaurant between \( 5:00 \) and \( 6:00 \) P.M.The one who arrives first will wait \( 15 \) minutes for the other, and then will leave (see figure). What is the probability that the two of you will actually meet,assuming that your arrival times are random within the hour?
What do you think about this solution?
We value your feedback to improve our textbook solutions.