/*! 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} Problem 25 How many three-letter (unordered... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

How many three-letter (unordered) sets are possible that use the letters \(\mathrm{q}, \mathrm{u}, \mathrm{a}, \mathrm{k}, \mathrm{e}, \mathrm{s}\) at most once each?

Short Answer

Expert verified
There are 20 three-letter unordered sets possible using the letters q, u, a, k, e, s at most once each. We found this by applying the combination formula \(C(6, 3) = \frac{6!}{3!(6-3)!}\) and calculating the required factorials.

Step by step solution

01

Understand the combination formula

The combination formula helps us calculate the number of possible combinations (unordered sets) of a larger set (in this case, the set of six letters). The combination formula is given by: \(C(n, r) = \frac{n!}{r!(n-r)!}\) where C(n, r) is the number of combinations of n things taken r at a time, n! is the factorial of n, and r! is the factorial of r.
02

Identify n and r values

In our problem, the set of letters (q, u, a, k, e, s) has a total of 6 elements, so n = 6. We need to create three-letter combinations from this set, so r = 3.
03

Apply the combination formula

We can now apply the combination formula to our problem, using n = 6 and r = 3: \(C(6, 3) = \frac{6!}{3!(6-3)!}\)
04

Calculate the factorials

We need to calculate the factorial values for 6!, 3!, and (6-3)!: 6! = 6 × 5 × 4 × 3 × 2 × 1 = 720 3! = 3 × 2 × 1 = 6 (6-3)! = 3! (since it evaluates to the same as 3!) = 6
05

Plug in the factorial values

Now, substitute the calculated factorials back into the combination formula: \(C(6, 3) = \frac{720}{6 \times 6}\)
06

Calculate the final result

We now calculate the total number of three-letter unordered sets: \(C(6, 3) = \frac{720}{36} = 20\) So, there are 20 three-letter unordered sets possible using the given letters at most once each.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Day traders typically buy and sell stocks (or other investment instruments) during the trading day and sell all investments by the end of the day. Exercises 57 and 58 are based on the following table, which shows the closing prices on January 9, 2009, of 12 stocks selected by your broker, Prudence Swift, as well as the change that day.$$\begin{array}{|l|c|c|}\hline \text { Tech Stocks } & \text { Close } & \text { Change } \\\\\hline \text { AAPL (Apple) } & \$ 90.58 & -2.12 \\\\\hline \text { MSFT (Microsoft) } & \$ 19.52 & -0.60 \\\\\hline \text { NOK (Nokia) } & \$ 15.21 & -0.16 \\\\\hline \text { NT (Nortel) } & \$ 0.39 & 0.10 \\\\\hline \text { RIMM (Research in Motion) } & \$ 47.99 & 1.49 \\\\\hline \text { S (Sprint Nextel) } & \$ 2.59 & 0.01 \\\\\hline \text { Non-Tech Stocks } & & \\\\\hline \text { DIS (Walt Disney) } & \$ 22.31 & -0.59 \\\\\hline \text { DUK (Duke) } & \$ 15.27 & -0.14 \\\\\hline \text { ED (Con Ed) } & \$ 39.66 & 0.20 \\\\\hline \text { FE (First Energy) } & \$ 48.90 & 1.14 \\\\\hline \text { MO (Altria Group) } & \$ 15.48 & 0.38 \\\\\hline \text { NVS (Novarnis) } & \$ 48.16 & -1.46 \\\\\hline\end{array}$$ On the morning of January 9,2009 , Swift advised you to purchase a collection of three tech stocks and two non-tech stocks, all chosen at random from those listed in the table. You were to sell all the stocks at the end of the trading day. a. How many possible collections are possible? b. You tend to have bad luck with stocks - they usually start going down the moment you buy them. How many of the collections in part (a) consist entirely of stocks that declined in value by the end of the day? c. Using the answers to parts (a) and (b), what would you say your chances were of choosing a collection consisting entirely of stocks that declined in value by the end of the day?

A poker hand consists of five cards from a standard deck of 52. (See the chart preceding Example 8.) , find the number of different poker hands of the specified type. Three of a kind (three of one denomination, one of another denomination, and one of a third)

You sell iPods \({ }^{\circledast}\) and \(j\) Pods. Let \(I\) be the set of all iPods you sold last year, and let \(J\) be the set of all jPods you sold last year. What set represents the collection of all iPods and jPods you sold combined?

(Some familiarity with linear programming is assumed for this exercise.) Before the advent of the simplex method for solving linear programming problems, the following method was used: Suppose you have a linear programming problem with three unknowns and 20 constraints. You locate corner points as follows: Selecting three of the constraints, you turn them into equations (by replacing the inequalities with equalities), solve the resulting system of three equations in three unknowns, and then check to see whether the solution is feasible. a. How many systems of three equations in three unknowns will you be required to solve? b. Generalize this to \(n\) constraints.

A poker hand consists of five cards from a standard deck of 52. (See the chart preceding Example 8.) , find the number of different poker hands of the specified type. Two of a kind (two of one denomination and three of different denominations)

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.