Free Q&A
Aptitude and Reasoning
General Knowledge
Puzzles
Interviews
Technical
Certifications
Exams
Job Roles
True or False

Login

Forgot Password?

Home/
Aptitude and Reasoning/
Quantitative Aptitude - Arithmetic Ability/
Probability /
Question

An urn contains 4 white 6 black and 8 red balls . If 3 balls are drawn one by one without replacement, find the probability of getting all white balls.

A) 5/204	B) 1/204
C) 13/204	D) None of these

Answer: B) 1/204

Explanation:

Let A, B, C be the events of getting a white ball in first, second and third draw respectively, then

Required probability = $P (A \cap B \cap C)$

= $P (A) P (\frac{B}{A}) P (\frac{C}{A \cap B})$

Now, P(A) = Probability of drawing a white ball in first draw = 4/18 = 2/9

When a white ball is drawn in the first draw there are 17 balls left in the urn, out of which 3 are white

$∴ P (\frac{B}{A}) = \frac{3}{17}$

Since the ball drawn is not replaced, therefore after drawing a white ball in the second draw there are 16 balls left in the urn, out of which 2 are white.

$∴ P (\frac{C}{A \cap B}) = \frac{2}{16} = \frac{1}{8}$

Hence the required probability = $\frac{2}{9} \times \frac{3}{17} \times \frac{1}{8} = \frac{1}{204}$

Subject: Probability

Related Questions

Find the range and mode of the data 17, 18, 28, 19, 16, 18, 17, 29, 18

A) 12 and 18	B) 13 and 18
C) 12 and 17	D) 11 and 17

A) 12 and 18

B) 13 and 18

C) 12 and 17

D) 11 and 17

Answer & Explanation Answer: B) 13 and 18

Explanation:

Report Error

View Answer Report Error Discuss

Filed Under: Probability
Exam Prep: Bank Exams

26 1679

Find the standard deviation of {11, 7, 10,13, 9}

A) 1	B) 2
C) 4	D) 5

A) 1

B) 2

C) 4

D) 5

Answer & Explanation Answer: B) 2

Explanation:

Report Error

View Answer Report Error Discuss

Filed Under: Probability
Exam Prep: Bank Exams

7 1199

A table tennis player, lost 12 games out of 18 games played. Calculate the games won in terms of decimal.

A) 0.667	B) 0.067
C) 0.50	D) 0.333

A) 0.667

B) 0.067

C) 0.50

D) 0.333

Answer & Explanation Answer: D) 0.333

Explanation:

Report Error

View Answer Report Error Discuss

Filed Under: Probability
Exam Prep: Bank Exams

6 1067

A sequence $a, ax, {ax}^{2}, . . . . . ., {ax}^{n}$ , has odd number of terms. Then the median is

A) axn2+1	B) axn2-1
C) axn-1	D) axn2

A) axn2+1

B) axn2-1

C) axn-1

D) axn2

Answer & Explanation Answer: D) axn2

Explanation:

Report Error

View Answer Report Error Discuss

Filed Under: Probability
Exam Prep: Bank Exams

6 12729

The mean of a distribution is 15 and the standard deviation is 5. What is the value of the coefficient variation?

A) 16.66%	B) 66.66%
C) 33.33%	D) 100%

A) 16.66%

B) 66.66%

C) 33.33%

D) 100%

Answer & Explanation Answer: C) 33.33%

Explanation:

Report Error

View Answer Report Error Discuss

Filed Under: Probability
Exam Prep: Bank Exams

8 1087

If the standard deviation of a population is 3, what would be the population variance?

A) 9	B) 6
C) 8	D) 15

A) 9

B) 6

C) 8

D) 15

Answer & Explanation Answer: A) 9

Explanation:

Report Error

View Answer Report Error Discuss

Filed Under: Probability
Exam Prep: Bank Exams

7 9931

The variance of a set of data is 169. Then the standard deviation of the data is

A) +-13	B) 13
C) 69	D) 84.5

A) +-13

B) 13

C) 69

D) 84.5

Answer & Explanation Answer: B) 13

Explanation:

Report Error

View Answer Report Error Discuss

Filed Under: Probability
Exam Prep: Bank Exams

6 8388

If the standard deviation of a population is 10, what would be the population variance?

A) 100	B) 30
C) 5	D) 20

A) 100

B) 30

C) 5

D) 20

Answer & Explanation Answer: A) 100

Explanation:

Report Error

View Answer Report Error Discuss

Filed Under: Probability
Exam Prep: Bank Exams

10 1123

Quick Links

About Us

Advertise with Us

Study Material