Sawaal
366
Q:

Two cards are drawn at random from a pack of 52 cards.what is the probability that either both are black or both are queen?

A) 52/221 B) 55/190
C) 55/221 D) 19/221

Answer:   C) 55/221



Explanation:

We have n(s) =52C2 52 = 52*51/2*1= 1326. 

Let A = event of getting both black cards 

     B = event of getting both queens 

A∩B = event of getting queen of black cards 

n(A) = 52*512*1 = 26C2 = 325, n(B)= 26*252*1= 4*3/2*1= 6  and  n(A∩B) = 4C2 = 1 

P(A) = n(A)/n(S) = 325/1326;

P(B) = n(B)/n(S) = 6/1326 and 

P(A∩B) = n(A∩B)/n(S) = 1/1326 

P(A∪B) = P(A) + P(B) - P(A∩B) = (325+6-1) / 1326 = 330/1326 = 55/221

Subject: Probability
Related Questions
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
Exam Prep: Bank Exams

26 1677
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
Exam Prep: Bank Exams

7 1199
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
Exam Prep: Bank Exams

6 1066
Q:

A sequence a, ax, ax2, ......, axn, has odd number of terms. Then the median is

 

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 12725
Q:

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%
 
Answer & Explanation Answer: C) 33.33%

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Probability
Exam Prep: Bank Exams

8 1087
Q:

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

 

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 9927
Q:

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
 
Answer & Explanation Answer: B) 13

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Probability
Exam Prep: Bank Exams

6 8386
Q:

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

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 1122