/*! 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 39 You roll a fair die three times.... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

You roll a fair die three times. What is the probability that a) you roll all 6 's? b) you roll all odd numbers? c) none of your rolls gets a number divisible by \(3 ?\) d) you roll at least one \(5 ?\) e) the numbers you roll are not all 5 's?

Short Answer

Expert verified
a) \(\frac{1}{216}\), b) \(\frac{1}{8}\), c) \(\frac{8}{27}\), d) \(\frac{91}{216}\), e) \(\frac{215}{216}\).

Step by step solution

01

Understanding the Experiment

The experiment involves rolling a fair six-sided die three times. The die has sides numbered from 1 to 6. For each roll, the outcome is independent of the previous rolls.
02

Calculating Probability for All 6's (a)

The probability of rolling a 6 on a fair die in a single roll is \( \frac{1}{6} \). For three independent rolls, the probability of rolling 6's each time is: \[ \left( \frac{1}{6} \right)^3 = \frac{1}{216} \]
03

Calculating Probability for All Odd Numbers (b)

The odd numbers on a die are 1, 3, and 5. The probability of rolling an odd number is \( \frac{3}{6} = \frac{1}{2} \). For three independent rolls, the probability of rolling odd numbers each time is: \[ \left( \frac{1}{2} \right)^3 = \frac{1}{8} \]
04

Calculating Probability for No Number Divisible by 3 (c)

Numbers divisible by 3 are 3 and 6. Thus, the numbers not divisible by 3 are 1, 2, 4, and 5. The probability of getting a number not divisible by 3 is \( \frac{4}{6} = \frac{2}{3} \). For three rolls: \[ \left( \frac{2}{3} \right)^3 = \frac{8}{27} \]
05

Calculating Probability for At Least One 5 (d)

First, calculate the probability of not rolling a 5 in a single roll: \( \frac{5}{6} \). The probability of not rolling a 5 in all three rolls is: \( \left( \frac{5}{6} \right)^3 = \frac{125}{216} \). The probability of at least one 5 is: \[ 1 - \frac{125}{216} = \frac{91}{216} \]
06

Calculating Probability for Not All 5's (e)

The probability of rolling all 5's is \( \left( \frac{1}{6} \right)^3 = \frac{1}{216} \). Then, the probability of not rolling all 5's is: \[ 1 - \frac{1}{216} = \frac{215}{216} \]

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!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Independent Events
In probability, independent events are those whose outcomes do not affect each other. When rolling a die multiple times, each roll is independent because the outcome of one roll does not influence the next. This means:
  • The probability of getting a certain number on one roll is unaffected by what numbers were rolled before.
  • When calculating probabilities for independent events, you multiply the probabilities of individual events.
For example, rolling a six three times involves independent events where the probability of rolling a six on each roll is \(\frac{1}{6}\). Therefore, you multiply this probability for each roll to find the total probability.
Probability Calculation
Probability is the measure of how likely an event is to occur. It is calculated by dividing the number of favorable outcomes by the total number of possible outcomes. For a fair six-sided die:
  • The probability of rolling any specific number, such as a six, is \(\frac{1}{6}\) because there is one favorable outcome and six possible outcomes.
  • To find the probability of rolling a number like an odd number, add up all favorable outcomes and divide by the total. Odd numbers on a die are 1, 3, and 5, so the probability is \(\frac{3}{6} = \frac{1}{2}\).
  • If you want the probability of not rolling a number divisible by 3, first count outcomes not divisible by 3 (1, 2, 4, 5) and use \(\frac{4}{6} = \frac{2}{3}\).
When faced with multiple events, these probabilities are often multiplied due to the independence of each event.
Dice Probability
Dice probability explores the chances of outcomes when rolling a die.
  • Each face of a six-sided die has an equal chance of landing face up, which is \(\frac{1}{6}\).
  • When rolling multiple times, each roll is independent, hence you can multiply the probabilities of individual outcomes.
  • For sequences like rolling odd numbers three times, calculate \( \left( \frac{1}{2} \right)^3 \), representing the chance on each of the three rolls.
  • Complementary events like "at least one five" involve calculating the probability of the opposite happening (no fives) and subtracting from one. \(1 - \left( \frac{5}{6} \right)^3\) meters the odds of rolling at least one five.
These concepts help in tackling more complex questions concerning dice probability scenarios.
Combinatorics
Combinatorics deals with counting possibilities and configurations, vital for solving probability problems. In dice rolling:
  • Each roll offers six possibilities, meaning three rolls provide \(6 \times 6 \times 6 = 216\) total combinations.
  • To determine how certain combinations, like all of one number, can occur, reduce possibilities. For example, all fives can occur in only one way (5, 5, 5), leading to \(\frac{1}{216}\).
  • When needing combinations where at least one roll matches a condition, use complementary counting. Calculate the opposite (none match) and subtract from total combinations.
Understanding these principles helps in both simple and complex probability calculations by structuring and recognizing all possible outcomes efficiently.

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

For each of the following, list the sample space and tell whether you think the events are equally likely: a) Roll two dice; record the sum of the numbers. b) A family has 3 children; record each child's sex in order of birth. c) Toss four coins; record the number of tails. d) Toss a coin 10 times; record the length of the longest run of heads.

For a sales promotion, the manufacturer places winning symbols under the caps of \(10 \%\) of all Pepsi bottles. You buy a six-pack. What is the probability that you win something?

On February \(11,2009,\) the AP news wire released the following story: (LAS VEGAS, Nev.) - A man in town to watch the NCAA basketball tournament hit a \(\$ 38.7\) million jackpot on Friday, the biggest slot machine payout ever. The 25 -year-old software engineer from Los Angeles, whose name was not released at his request, won after putting three \(\$ 1\) coins in a machine at the Excalibur hotel-casino, said Rick Sorensen, a spokesman for slot machine maker International Game Technology. a) How can the Excalibur afford to give away millions of dollars on a \(\$ 3\) bet? b) Why was the maker willing to make a statement? Wouldn't most businesses want to keep such a huge loss quiet?

Suppose that \(46 \%\) of families living in a certain county own a computer and \(18 \%\) own an HDTV. The Addition Rule might suggest, then, that \(64 \%\) of families own either a computer or an HDTV. What's wrong with that reasoning?

\(A 2010\) study conducted by the National Center for Health Statistics found that \(25 \%\) of U.S. households had no landline service. This raises concerns about the accuracy of certain surveys, as they depend on random-digit dialing to households via landlines. We are going to pick five U.S. households at random: a) What is the probability that all five of them have a landline? b) What is the probability that at least one of them does not have a landline? c) What is the probability that at least one of them does have a landline?

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.