There are 12 white and 12 red balls in a bag. Balls are drawn one by one with replacement from the bag. What is the probability that 7th drawn ball is 4th white ball ?

Asked by Last Modified  

9 Answers

Learn Class XI-XII Tuition (PUC)

Follow 0
Answer

Please enter your answer

G Prasad

Tutor

To find: The probability that the 7th ball drawn is the 4th white ball. Solution: Probability of getting a white ball per draw is 1/2. Probability of getting a red ball per draw is 1/2. As the balls are replaced after every draw, this probability does not change. Now for a clear understanding...
read more
To find: The probability that the 7th ball drawn is the 4th white ball. Solution: Probability of getting a white ball per draw is 1/2. Probability of getting a red ball per draw is 1/2. As the balls are replaced after every draw, this probability does not change. Now for a clear understanding let us consider each draw as an event. there are total seven events. _ _ _ _ _ _ _. For the seventh event to be a white ball, the previous six events should contain 3 white balls and 3 red balls in any random arrangement. The number of ways for this is 6C3 (1/2)^3 * (1/2)^3 [6C3 is the number of ways to select 3 places out of 6 places. (1/2)^3 is probability of getting 3 white balls and the second (1/2)^3 is the probability of getting three red balls]. = [(6*5*4)/(3*2*1)] * (1/64) = 5/16. Now for the seventh ball to be white the probability is 1/2. So, total probability = (5/16)*(1/2) = 5/32 read less
Comments
Dislike Bookmark

Math Educator for Std.11th ,12th , Engineering Entrance and Degree Level with 11+ Years Experience

the probability that 7th drawn ball is 4th white ball = 1/2
Comments
Dislike Bookmark

Science teacher

red
Comments
Dislike Bookmark

Headstart to assured 95+ score in math

It's a bit lengthy. I will post a pic of solution in my gallery.
Comments
Dislike Bookmark

Spoken English, BTech Tuition, C Language, C++ Language, CAD etc., with 4 years of experience

P(A) = 12/24=1/2, P(B)= 12/24= 1/2, White ball is drawn 4th time in 7th draw i.e, already 6 draws are completed in which 3 white balls are already drawn. Required probability is: 6C3 p^3 q^3 p^1, where p is drawing white ball, q is drawing red ball. =5/32.
Comments
Dislike Bookmark

Physics and Maths made easy

Dear Akshay, The answer is too long and my answer reached the status of a research paper. But, however, I came to know this problem is of a category namely Markov's chain and so there was nothing new in my paper. Markov's chain come in because each draw (after the first one) depends on the outcomes...
read more
Dear Akshay, The answer is too long and my answer reached the status of a research paper. But, however, I came to know this problem is of a category namely Markov's chain and so there was nothing new in my paper. Markov's chain come in because each draw (after the first one) depends on the outcomes of the previous draws, as you said second ball drawn (and onwards) replaces the previously drawn ball (hence the previously drawn ball remains outside deciding the number of white and red balls from which the fresh drawing of a ball is done). Any way, thanks for the question as it improved my knowledge tremendously. read less
Comments
Dislike Bookmark

Data Analytics & Advanced Statistics Tutor with 18 years of experience in teaching

Here P(white ball)=1/2 .Then required probability = 6C3 *(1/2)^4 *(1/2)^3 = 0.15625.(By Negative Binomial distribution)
Comments
Dislike Bookmark

Teaching is my passion!!!!

Probability is 1/2
Comments
Dislike Bookmark

Trainer

Solution: P(w) = 12/24=1/2, P(R)= 12/24= 1/2, White ball is drawn 4th time in 7th draw means, already 6 draws are completed in which 3 white balls are already drawn. Required probability is: 6C3 p^3 q^3 p^1, where p is drawing white ball, q is drawing red ball. =5/32
Comments
Dislike Bookmark

View 7 more Answers

Related Questions

The wave which require no medium for the propagation are known as __________. (Sound waves, Mechanical waves, Electromagnetic waves, None of these)
Electromagnetic waves
Narendra Kumar
How can I start conducting online tuition?
u can register as online tutor, the student those who are willing for e-learning they will inbox you,in that way u can start online tuition .
Shainaj S.
how to clear KARNATAKA PUC MATHS IN ONE MONTH(old syllabus)
No way you can cover a Math syllabus in 1 Month. Yet, you can try by starting each chapter with writing down the formula. Solve Algebra then graph then theorem then tree, mapping scheme and so on. You...
Rockysourabh
0 0
5
Why does a swimmer push the water backwards?
According to newton's 3rd law of motion in each and every action there is an equal and opposite force. So if he push the water backwards then according to the above principle or law he will be able to move forward.
Gulfam
0 0
6
Important question of physics 2 what is moment of inertia 3 what is relation between llinear momentun and angular momentum
MOMENT OF INERTIA is a quantity expressing a body's tendency to resist angular acceleration, which is the sum of the products of the mass of each particle in the body with the square of its distance from...
Abdhesh

Now ask question in any of the 1000+ Categories, and get Answers from Tutors and Trainers on UrbanPro.com

Ask a Question

Related Lessons

Accounting for partnership: Basic concept
QUESTIONS: Define Partnership Deed. Answer: A partnership deed is an agreement among the partners which contains ai! the terms of the Partnership. It generally contains the details about all the...

Deepika Agrawal

0 0
1
Co-operative Society And Types Of Co-op Societies-Class 11/12,Business Studies/OC
HSC

Rajiv Vadera

0 0
0
Key to Success in Mathematics
Following are keys to success in any mathematics exam: 1. Learn how formulas are derived. 2. Types of Interpretations of formulas. 3. Selected Examples to represent types of problems. 4. Good books...

Nilaish

0 0
0
Parabola
f (x) = a(x - h)2 + k, where (h, k) is thevertex of the parabola. FYI: Different textbooks have different interpretations of the reference "standard form" of a quadratic function. Some say f (x) = ax2...

Sameer Ninawe

1 0
0
Process Costing
Introduction Process Costing is a method of Costing used in industries where the material has to pass through two or more processes for being converted into final product. It is defined as a method...

Fr Prashanth Reddy

Recommended Articles

Meet Mohammad Wazid, a skilled trainer for...

Mohammad Wazid is a certified professional tutor for class 11 students. He has 6 years of teaching experience which he couples with an energetic attitude and a vision of making any subject easy for the students. Over the years he has developed skills with a capability of understanding the requirements of the students. This...

Read full article >

Meet Raghunandan.G.H, a B. Tech Tutor from...

Raghunandan is a passionate teacher with a decade of teaching experience. Being a skilled trainer with extensive knowledge, he provides high-quality BTech, Class 10 and Class 12 tuition classes. His methods of teaching with real-time examples makes difficult topics simple to understand. He explains every concept in-detail...

Read full article >

Meet Sandhya R, a B.Sc tutor from Bangalore

Sandhya is a proactive educationalist. She conducts classes for CBSE, PUC, ICSE, I.B. and IGCSE. Having a 6-year experience in teaching, she connects with her students and provides tutoring as per their understanding. She mentors her students personally and strives them to achieve their goals with ease. Being an enthusiastic...

Read full article >

Meet Radhe Shyam Burman, an MBA Tutor from...

Radhe Shyam is a highly skilled accounts and finance trainer with 8 years of experience in teaching. Accounting is challenging for many students and that’s where Radhe Shyam’s expertise comes into play. He helps his students not only in understanding the subject but also advises them on how to overcome the fear of accounts...

Read full article >

Find Class 12 Tuition near you
Class 12 Tuition in Delhi
Class 12 Tuition in Bangalore
Class 12 Tuition in Hyderabad
Class 12 Tuition in Chennai
Class 12 Tuition in Kolkata
Class 12 Tuition in Mumbai
Class 12 Tuition in Pune
Class 12 Tuition in Noida
Class 12 Tuition in Gurgaon
Class 12 Tuition in Lucknow
Online Tuition Class 12

Looking for Class 12 Tuition ?

Learn from the Best Tutors on UrbanPro

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you