JEE Exam > JEE Questions > A box contains 5 black and 4 white balls. A ...
Start Learning for Free
A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, is
- a)7/11
- b)5/11
- c)53/99
- d)48/99
Correct answer is option 'C'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
A box contains 5 black and 4 white balls. A ball is drawn at random a...
Most Upvoted Answer
A box contains 5 black and 4 white balls. A ball is drawn at random a...
Solution:
Initial probability of drawing a black ball = P(B) = 5/9
Initial probability of drawing a white ball = P(W) = 4/9
After putting the ball back along with two additional balls of opposite colour, the total number of balls in the box becomes 9+2 = 11.
Now, there are two cases to consider:
Case 1: The first ball drawn is black
After putting the black ball back, the number of black balls in the box becomes 5+2 = 7 and the number of white balls becomes 4+1 = 5.
Probability of drawing a black ball in this case = P(B)×P(B|first ball is black)
= (5/9)×(7/11)
= 35/99
Case 2: The first ball drawn is white
After putting the white ball back, the number of black balls in the box becomes 5+1 = 6 and the number of white balls becomes 4+2 = 6.
Probability of drawing a black ball in this case = P(W)×P(B|first ball is white)
= (4/9)×(6/11)
= 24/99
Total probability of drawing a black ball in the second draw = Probability in case 1 + Probability in case 2
= (35/99) + (24/99)
= 59/99
Therefore, the probability that the ball drawn now is black is 53/99.
Answer: (c) 53/99
Initial probability of drawing a black ball = P(B) = 5/9
Initial probability of drawing a white ball = P(W) = 4/9
After putting the ball back along with two additional balls of opposite colour, the total number of balls in the box becomes 9+2 = 11.
Now, there are two cases to consider:
Case 1: The first ball drawn is black
After putting the black ball back, the number of black balls in the box becomes 5+2 = 7 and the number of white balls becomes 4+1 = 5.
Probability of drawing a black ball in this case = P(B)×P(B|first ball is black)
= (5/9)×(7/11)
= 35/99
Case 2: The first ball drawn is white
After putting the white ball back, the number of black balls in the box becomes 5+1 = 6 and the number of white balls becomes 4+2 = 6.
Probability of drawing a black ball in this case = P(W)×P(B|first ball is white)
= (4/9)×(6/11)
= 24/99
Total probability of drawing a black ball in the second draw = Probability in case 1 + Probability in case 2
= (35/99) + (24/99)
= 59/99
Therefore, the probability that the ball drawn now is black is 53/99.
Answer: (c) 53/99
Free Test
FREE
| Start Free Test |
Community Answer
A box contains 5 black and 4 white balls. A ball is drawn at random a...
Attention JEE Students!
To make sure you are not studying endlessly, EduRev has designed JEE study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in JEE.
|
Explore Courses for JEE exam
|
|
Similar JEE Doubts
Top Courses for JEEView all
A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, isa) 7/11b) 5/11c) 53/99d) 48/99Correct answer is option 'C'. Can you explain this answer?
Question Description
A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, isa) 7/11b) 5/11c) 53/99d) 48/99Correct answer is option 'C'. Can you explain this answer? for JEE 2024 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, isa) 7/11b) 5/11c) 53/99d) 48/99Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for JEE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, isa) 7/11b) 5/11c) 53/99d) 48/99Correct answer is option 'C'. Can you explain this answer?.
A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, isa) 7/11b) 5/11c) 53/99d) 48/99Correct answer is option 'C'. Can you explain this answer? for JEE 2024 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, isa) 7/11b) 5/11c) 53/99d) 48/99Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for JEE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, isa) 7/11b) 5/11c) 53/99d) 48/99Correct answer is option 'C'. Can you explain this answer?.
Solutions for A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, isa) 7/11b) 5/11c) 53/99d) 48/99Correct answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for JEE.
Download more important topics, notes, lectures and mock test series for JEE Exam by signing up for free.
Here you can find the meaning of A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, isa) 7/11b) 5/11c) 53/99d) 48/99Correct answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, isa) 7/11b) 5/11c) 53/99d) 48/99Correct answer is option 'C'. Can you explain this answer?, a detailed solution for A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, isa) 7/11b) 5/11c) 53/99d) 48/99Correct answer is option 'C'. Can you explain this answer? has been provided alongside types of A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, isa) 7/11b) 5/11c) 53/99d) 48/99Correct answer is option 'C'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice A box contains 5 black and 4 white balls. A ball is drawn at random and its colour is noted. The ball is then put back in the box along with two additional balls of its opposite colour. If a ball is drawn again from the box, then the probability that the ball drawn now is black, isa) 7/11b) 5/11c) 53/99d) 48/99Correct answer is option 'C'. Can you explain this answer? tests, examples and also practice JEE tests.
|
|
Explore Courses for JEE exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup