Quant Exam  >  Quant Questions  >  A bag contains four black and five red balls.... Start Learning for Free
A bag contains four black and five red balls. If three balls from the bag are chosen at random, what is the chance that they are all black?
  • a)
    1/21
  • b)
    1/20
  • c)
    2/23
  • d)
    1/9
Correct answer is option 'A'. Can you explain this answer?
Verified Answer
A bag contains four black and five red balls. If three balls from the ...
Black and Black and Black = 4/9 x 3/8 x 2/7 = 23/504 = 1/21.
View all questions of this test
Most Upvoted Answer
A bag contains four black and five red balls. If three balls from the ...
**Problem Analysis**
We are given a bag containing four black and five red balls. We need to find the probability that when three balls are chosen randomly from the bag, they are all black.

**Total Number of Outcomes**
The total number of ways to choose three balls from nine balls is given by the combination formula C(n, r), where n is the total number of balls and r is the number of balls to be chosen. In this case, n = 9 and r = 3, so the total number of outcomes is C(9, 3) = 9! / (3! * (9-3)!) = 84.

**Favorable Outcomes**
To find the number of favorable outcomes, we need to consider the situation where all three balls chosen are black. Since there are four black balls in the bag, the number of ways to choose three black balls is C(4, 3) = 4! / (3! * (4-3)!) = 4.

**Probability Calculation**
The probability of an event occurring is given by the ratio of the number of favorable outcomes to the number of total outcomes. In this case, the probability of choosing three black balls is 4/84 = 1/21.

**Answer**
Therefore, the chance that all three balls chosen at random from the bag are black is 1/21. Hence, the correct answer is option A.
Explore Courses for Quant exam
Question Description
A bag contains four black and five red balls. If three balls from the bag are chosen at random, what is the chance that they are all black?a)1/21b)1/20c)2/23d)1/9Correct answer is option 'A'. Can you explain this answer? for Quant 2025 is part of Quant preparation. The Question and answers have been prepared according to the Quant exam syllabus. Information about A bag contains four black and five red balls. If three balls from the bag are chosen at random, what is the chance that they are all black?a)1/21b)1/20c)2/23d)1/9Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for Quant 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A bag contains four black and five red balls. If three balls from the bag are chosen at random, what is the chance that they are all black?a)1/21b)1/20c)2/23d)1/9Correct answer is option 'A'. Can you explain this answer?.
Solutions for A bag contains four black and five red balls. If three balls from the bag are chosen at random, what is the chance that they are all black?a)1/21b)1/20c)2/23d)1/9Correct answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for Quant. Download more important topics, notes, lectures and mock test series for Quant Exam by signing up for free.
Here you can find the meaning of A bag contains four black and five red balls. If three balls from the bag are chosen at random, what is the chance that they are all black?a)1/21b)1/20c)2/23d)1/9Correct answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of A bag contains four black and five red balls. If three balls from the bag are chosen at random, what is the chance that they are all black?a)1/21b)1/20c)2/23d)1/9Correct answer is option 'A'. Can you explain this answer?, a detailed solution for A bag contains four black and five red balls. If three balls from the bag are chosen at random, what is the chance that they are all black?a)1/21b)1/20c)2/23d)1/9Correct answer is option 'A'. Can you explain this answer? has been provided alongside types of A bag contains four black and five red balls. If three balls from the bag are chosen at random, what is the chance that they are all black?a)1/21b)1/20c)2/23d)1/9Correct answer is option 'A'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A bag contains four black and five red balls. If three balls from the bag are chosen at random, what is the chance that they are all black?a)1/21b)1/20c)2/23d)1/9Correct answer is option 'A'. Can you explain this answer? tests, examples and also practice Quant tests.
Explore Courses for Quant exam

Top Courses for Quant

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev