My Math Forum  

Go Back   My Math Forum > High School Math Forum > Probability and Statistics

Probability and Statistics Basic Probability and Statistics Math Forum


Reply
 
LinkBack Thread Tools Display Modes
April 2nd, 2012, 01:40 AM   #1
Newbie
 
Joined: Apr 2012

Posts: 7
Thanks: 0

Confusing probability question

A student is taking a multiple-choice exam in which each question has 4 choices. Assuming that she has no knowledge of the correct answers to any of the questions, she has decided on a strategy in which she will place 4 balls (marked A,B,C,D) into a box. She randomly selects 1 ball for each question and replaces the ball in the box. The marking on the ball will determine her answer to the question. There are 4 multiple choice questions on the exam.

(a) What is the probability that she will get 4 questions correct?
(b) At least 3 questions correct?
(c) No more than 2 questions correct?

My teacher left early since he had to go somewhere, so he didn't explain to us how to do this question. Again, much help would be very appreciated!
HungerGames1 is offline  
 
April 2nd, 2012, 06:39 AM   #2
Newbie
 
Joined: Apr 2012

Posts: 7
Thanks: 0

Re: Confusing probability question

Attempted to work these out. But my brain is all clustered atm.. I really need to work on my probability/mathematics skills.
(a) If it's a 1/4 chance of getting one right for each qq. 4 qq's = 16 possible chances, so 4/16 to get 4 qq's correct. (25%)?
(b) Confused with the wording [at least 3 qq's correct]
(c) Confused with the wording for this as well [no more than 2 qq's correct]
HungerGames1 is offline  
April 2nd, 2012, 06:44 AM   #3
Global Moderator
 
greg1313's Avatar
 
Joined: Oct 2008
From: London, Ontario, Canada - The Forest City

Posts: 7,881
Thanks: 1088

Math Focus: Elementary mathematics and beyond
Re: Confusing probability question

Quote:
Originally Posted by HungerGames1
(a) If it's a 1/4 chance of getting one right for each qq. 4 qq's = 16 possible chances, so 4/16 to get 4 qq's correct. (25%)?
1/4 * 1/4 * 1/4 * 1/4 = 1/256.
greg1313 is offline  
April 2nd, 2012, 07:40 AM   #4
Senior Member
 
Joined: Dec 2011

Posts: 277
Thanks: 1

Re: Confusing probability question

Quote:
Originally Posted by HungerGames1
Attempted to work these out. But my brain is all clustered atm.. I really need to work on my probability/mathematics skills.
(a) If it's a 1/4 chance of getting one right for each qq. 4 qq's = 16 possible chances, so 4/16 to get 4 qq's correct. (25%)?
(b) Confused with the wording [at least 3 qq's correct]
(c) Confused with the wording for this as well [no more than 2 qq's correct]
b.
Different people have different problem-solving style preferences.
Well, I'll just follow [color=#00BF00]greg1313[/color]'s approach.

P(At least 3 questions correct)
=P(3 questions correct or 4 questions correct)
=P(3 questions correct) or P(4 questions correct)
=P(3 questions correct and 1 wrong) or P(4 questions correct)
+ P(CCCC)" />





Isbell is offline  
Reply

  My Math Forum > High School Math Forum > Probability and Statistics

Tags
confusing, probability, question



Search tags for this page
a student is taking a multiple-choice exam in which each question has 5 choices. assuming that she has no knowledge of the correct answers to any of the questions, she has decided on a strategy in which she will place 5 balls (marked a, b, c, d, e) into
,

1. A Student is taking a multiple-choice exam in which each question has four choices. Assuming that she has no knowledge of the correct answers assuming that she has no knowledge of the correct answers to any of the questions, she has decided on a strate

,

1. A Student is taking a multiple-choice exam in which each question has four choices. Assuming that she has no knowledge of the correct answers assuming that she has no knowledge of the correct answers to any of the questions, she has decided on a strate

,

a student is taking a multiple choice exam in which each question has four choices

,

A student is appearing in a multiple- choice exam in which each question has four choices. Assuming that she has no knowledge of the correct answer to any of the questions, she has deciced on a strategy in which she will place four balls( marked A, B, C a

,

1. A student is taking a multiple-choice exam in which each question has four choices. Assume that the student has no knowledge of the correct answers to any of the questions. She has decided on a strategy in which she will place four balls (marked A, B,

,

A student is taking a multiple-choice exam in which each question has four choices. Assume that the student has no knowledge of the correct answers to any of the questions

,

A student is taking a multiple choice exam in which each question has four choices.

,

A student is taking a multiple-choice exam in which each question has 5 choices. Assuming that she has no knowledge of the correct answers to any of the questions, she has decided on a strategy in which she will place 5 balls (marked A, B, C, D, E) into

,

A student is taking a multiple-choice exam in which each question has 5 choices. Assuming that she has no knowledge of the correct answers to any of the questions, she has decided on a strategy in which she will place 5 balls (marked A, B, C, D, E) into

,

confusing multiple choice questions in probability

,

A student is appearing in a multiple-choice exam in which each question has four choices. Assuming that she has no knowledge of the correct answers to any of the questions, she has decided on a strategy in which she will place four balls (marked A, B, C

Click on a term to search for related topics.
Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
confusing probability questions hoyy1kolko Probability and Statistics 13 June 4th, 2011 05:22 PM
Probability question (hard and confusing) hoyy1kolko Probability and Statistics 9 May 18th, 2011 09:49 AM
Probability (confusing question) hoyy1kolko Probability and Statistics 5 April 15th, 2011 11:22 PM
Probability question(confusing) hoyy1kolko Probability and Statistics 1 April 9th, 2011 09:54 AM
Probability, help me, please, So confusing daivinhtran Probability and Statistics 1 March 29th, 2011 05:53 PM





Copyright © 2018 My Math Forum. All rights reserved.