Sawaal
67
Q:

A bag contains 4 red and 3 black balls. A second bag contains 2 red and 4 black balls. One bag is selected at random. From the selected bag, one ball is drawn. Find the probability that the ball drawn is red.

A) 23/42 B) 19/42
C) 7/32 D) 16/39

Answer:   B) 19/42



Explanation:

A red ball can be drawn in two mutually exclusive ways

 (i) Selecting bag I and then drawing a red ball from it.

 

(ii) Selecting bag II and then drawing a red ball from it.

 

Let E1, E2 and A denote the events defined as follows:

E1 = selecting bag I,

E2 = selecting bag II

A = drawing a red ball

Since one of the two bags is selected randomly, therefore 

P(E1) = 1/2  and  P(E2) = 1/2

Now, PAE1 = Probability of drawing a red ball when the first bag has been selected = 4/7

  PAE2  = Probability of drawing a red ball when the second bag has been selected = 2/6

 Using the law of total probability, we have 

 P(red ball) = P(A) = PE1×PAE1+PE2×PAE2 

 

                          = 12×47+12×26=1942

Subject: Probability - Quantitative Aptitude - Arithmetic Ability
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Analyst , Bank Clerk , Bank PO
Related Questions
Q:

If the standard deviation of 0, 1, 2, 3 ......... 9 is K, then the standard deviation of 10, 11, 12, 13 ........... 19 will be:

 

A) K+1 B) K
C) K+4 D) K+8
 
Answer & Explanation Answer: B) K

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Probability - Quantitative Aptitude - Arithmetic Ability
Exam Prep: Bank Exams

7 1687
Q:

The standard deviation of the set {10, 11, 12, 9, 8} is

A) 1 B) √2
C) 2 D) 2√2
 
Answer & Explanation Answer: B) √2

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Probability - Quantitative Aptitude - Arithmetic Ability
Exam Prep: Bank Exams

8 1565
Q:

Find the range of the data 2, 1, 2, 3, 5, 4, 7, 3, 5, 2, 4.

A) 5 B) 4
C) 3 D) 6
 
Answer & Explanation Answer: D) 6

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Probability - Quantitative Aptitude - Arithmetic Ability
Exam Prep: Bank Exams

2 1393
Q:

Find the median, mode and mean of 9, 5, 8, 9, 9, 7, 8, 9, 8.

A) 9, 9, 9 B) 9, 8, 9
C) 8, 9, 8 D) 8, 9, 9
 
Answer & Explanation Answer: C) 8, 9, 8

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Probability - Quantitative Aptitude - Arithmetic Ability
Exam Prep: Bank Exams

6 1417
Q:

In the usual set notation, A ∪ (B ∩ C) =

 

 

A) A∪B∪A∪C B) A∩B∪A∩C
C) A∪B∩A∪C D) A∪B∩A∩C
 
Answer & Explanation Answer: C) A∪B∩A∪C

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Probability - Quantitative Aptitude - Arithmetic Ability
Exam Prep: Bank Exams

2 5971
Q:

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
 
Answer & Explanation Answer: B) 13 and 18

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Probability - Quantitative Aptitude - Arithmetic Ability
Exam Prep: Bank Exams

3 1546
Q:

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

A) 1 B) 2
C) 4 D) 5
 
Answer & Explanation Answer: B) 2

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Probability - Quantitative Aptitude - Arithmetic Ability
Exam Prep: Bank Exams

3 1647
Q:

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
 
Answer & Explanation Answer: D) 0.333

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Probability - Quantitative Aptitude - Arithmetic Ability
Exam Prep: Bank Exams

3 1669