math

Beth Dahlke is taking a ten question multiple choice test for which each question has three answer choice only one of which is correct. Beth decides on answers by rolling a fair die and making the first answer choice if the die shows 1 or 2 the second if it showes 3 or 4 and the third if it showes 5 or 6. Find the probability of each event a) exactly fseven correct answers b) at least seven correct answers.

  1. 👍
  2. 👎
  3. 👁
  1. Prob of 1 or 2 on a die = 2/6 = 1/3
    prob of 2 or 4 = 1/3
    prob of 5 or 6 = 1/3

    Since these become your choice of answer
    prob of selecting 1st answer = 1/3
    prob of selecting 2nd answer = 1/3
    .....

    so the prob of choosing the correct answer in each event is simply 1/3

    so to get 7 out of 10 correct
    = C(10,7) (1/3)^7 (2/3)^3 = appr .01626

    so at least 7
    = C(10,7) (1/3)^7 (2/3)^3 + C(10,8) (1/3)^8 (2/3)^2 + .. + C(10,10) (1/3)^10

    I will let you do the button pushing

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Test taking Stratagies (2 questions) help me plz

    1.)Which of the following is a good way to approach answering an essay question on a test? A.)Start writing your answer as soon as you have read the question B.)Jot down a rough outline before you start writing**** C.)Write as

  2. EDTECH

    Which of the following is a good test-taking strategy for multiple-choice questions? A)answer C is almost always the correct answer, so pick answer C if you don't know the answer. B)read the answers first, then read the question.

  3. Algebra Probability PLEASE HELP

    You have a 5-question multiple-choice test. Each question has four choices. You don’t know any of the answers. What is the experimental probability that you will guess exactly three out of five questions correctly?

  4. math

    a multiple choice test has 8 questions with 4 possible answers for each question. if a student were to guess the answer to each question how many different ways would there be to answer the test A. 32 B. 4 C. 65 536 D. 4 096

  1. Math

    A multiple choice quiz contains five question. Each question has four answer choices. Michael is not prepared for the quiz and decides to guess for each question. What is the probability that Michael will get at least one question

  2. math

    Mr. McKay wrote an algebra test with a total of 15 questions consisting of multiple choice and short response style questions. Multiple choice questions, x, were worth 5 points each and short response questions, y, were worth 10

  3. business

    please help Which of the following is not a travel, hospitality, and tourism career? Chef Pilot Curator Truck Driver Question 3(Multiple Choice Worth 1 points) What is true about semi truck drivers? They often attend vocational

  4. math

    you take a three-question multiple-choice test.each question has four choices.you don't know any of the answers. what is the experimental probability that you will guess exactly two out of three correctly please help me i am

  1. Pre-Algebra 8th grade

    I need help with my homework that is due tomorrow. Question 1 (Multiple Choice Worth 1 points) (01.01 MC) Which decimal number best describes the fraction fraction 137 over 6? *** A repeating decimal 22.83 with a bar over 3 A

  2. Math (Algebra)

    Gretchen and Ezia received equal scores on a test made up of multiple choice questions and an essay. Gretchen got 18 multiple choice questions correct and received 19 points for her essay. Ezia got 15 multiple choice questions

  3. math

    Louann and Carla received equal scores on a test made up of multiple choice questions and an essay. Louann got 14 multiple choice questions correct and received 24 points for her essay. Carla got 16 multiple choice questions

  4. Statistics

    A 10 question test is all multiple choice. Each question has four choices. Determine the mean number of questions answered correctly as well as the standard deviation for the number of correct answers if someone were to guess on

You can view more similar questions or ask a new question.