SOLUTION: A Finite final consists of 30 multiple choice questions. If each question has 4 choices and 1 right answer, find the probability that a student gets an A (i.e. 27 or better) by pur

Algebra.Com
Question 1191245: A Finite final consists of 30 multiple choice questions. If each question has 4 choices and 1 right answer, find the probability that a student gets an A (i.e. 27 or better) by purely guessing on each question.
Answer by ikleyn(52835)   (Show Source): You can put this solution on YOUR website!
.
A Finite final consists of 30 multiple choice questions.
If each question has 4 choices and 1 right answer, find the probability
that a student gets an A (i.e. 27 or better) by purely guessing on each question.
~~~~~~~~~~~~~~~~~~~~~

For each individual multiple choice question of 30 multiple questions,


    the probability to guess correctly is   = 0.25;  

    the probability to guess incorrectly is   = 0.75.



Next,  P = P(27) + P(28) + P(29) + P(30) = use the formulas for the binomial distribution = 

         =  +  +  +  = 

         = 9.50802*10^(-14) + 3.39572*10^(-15) + 7.80626*10^(-17) + 8.67362*10^(-19) = 9.85548*10^(-14).     ANSWER


Solved.

----------------

If you want to see many similar  (or different)  solved problems,  look into the lessons
    - Simple and simplest probability problems on Binomial distribution
    - Typical binomial distribution probability problems
    - How to calculate Binomial probabilities with Technology (using MS Excel)
    - Solving problems on Binomial distribution with Technology (using MS Excel)
    - Solving problems on Binomial distribution with Technology (using online solver)
in this site.

After reading these lessons,  you will be able to solve such problems on your own,
which is your  PRIMARY  MAJOR  GOAL  visiting this forum  (I believe).



RELATED QUESTIONS

A test is composed of six multiple choice questions where each question has 4 choices. If (answered by edjones)
A test is composed of six multiple choice questions where each question has 4 choices. If (answered by stanbon)
A test is composed of six multiple choice questions where each question has 4 choices. If (answered by stanbon)
A test is composed of six multiple choice questions where each question has 4 choices. If (answered by solver91311)
A quiz has 4 multiple-choice questions. Each question has 5 choices, 1 being correct and... (answered by ikleyn,MathTherapy)
If a multiple-choice test consists of 5 questions each with 4 possible answers of which... (answered by stanbon)
A multiple-choice test consists of 7 questions. Each question has answer choices of a ,b (answered by Edwin McCravy)
The test consists of 15 questions. 10 are true/false questions and 5 are multiple choice (answered by solver91311)
A multiple-choice test has 6 questions. Each question has 5 choices and only one of which (answered by ikleyn)