let A= set of 3x3 determinat having entries +1 or -1, if a determinat A1 is chosen randomly from the set of A,then the probability that the product of the elements of any row or any column of A1 is -1 is _

2 years ago

Share

Answers : (2)

                                        

I am not sure, but here is my best guess.


 


 


Sample Space = 2^9


 


(There are 9 positions, each position has two possiblities (-1 or +1) )


 


Favourable Outcomes :


 


Number of -1 in each row or coloumn should be odd.


So we get two cases here.


(i) No. of -1 in each row and coloumn is 3


(ii) No. of -1 in each row and coloumn is 1


 


Case 1:


 


This case can occur only when all the elements in the matrix is -1.


 


No. of favourable cases = 1


 


Case 2:


 


Consider the matrix row wise.


In the first row, you can put the -1 in any of the 3 places.


In the second row, you can put the -1 in two places (no below the previous one)


In the third row, you can put the -1 in only one place (remaining one, not below the other two).


 


So you get 3*2*1 = 6 possibilities in this case.


 


Total no. of favourable outcome = 6+1 = 7


 


So required probability is 7/29 ..

2 years ago
                                        

Okay I missed a case.


 


All digits in a single row are -1. Rest of the elements are 1.


So we get 3 more cases.


 


So Probability = 10/2^9

2 years ago

Post Your Answer

More Questions On Algebra

Ask Experts

Have any Question? Ask Experts
Post Question
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!!
Click Here for details
Consider the two functions f(x) =x^2+2bx+1 and g(x)=2a(x+b), where the variable x and the constants a and b are real numbers. Each such pair of the constants a and b may be considered as a...
 
 
Hello student, Please find the answer to your question below Giventwo functions f(x) =x^2+2bx+1 and g(x)=2a(x+b), where the variable x and the constants a and b are real numbers. Each such...
  img
SHAIK AASIF AHAMED 3 months ago
Find all real values of m for which the inequalty mx 2 - 4x + 3m + 1 >0 is satisfied for all positive x. Hint : THE GIVEN EXPRESSION IS +VE ONLY AND ONLY FOR POSTIVE x.
 
 
Hello Student, Please find the solution The value of this quadratic is always positive (>0) So graph will always be above x-axis therefore the condition will be :- D>0 and a>0...
  img
Nishant Vora 2 months ago
Find all real values of m for which the inequalty mx 2 - 4x + 3m + 1 >0 is satisfied for all positive x.
 
 
Hello Student, Please find the solution The value of this quadratic is always positive (>0) So graph will always be above x-axis therefore the condition will be :- D>0 and a>0...
  img
Nishant Vora 2 months ago
Solve this question please …...........I am very eager to solve this
 
 
Hello student, Please find answer to your question For n,
  img
Jitender Singh 4 months ago
The no. of points on the line 3x+4y=5 which are at a distance of sec^2? +2cosec^2?,? belongs to R from the point (1,3).
 
 
Kindly define the question properly,too many question marks in between expression.
  img
Sunil Kumar 11 months ago
 
Hi Kindly clarify the question. What does the question mark represent ?
  img
Sunil Kumar 11 months ago
what is a scalar vector
 
 
Scalars are quantities that are fully described by a magnitude (or numerical value) alone. Vectors are quantities that are fully described by both a magnitude and a direction. A related...
  img
Saurabh Singh 9 months ago
 
Scalar Quantities Most of the physical quantities encountered in physics are either scalar or vector quantities. A scalar quantity is defined as a quantity that has magnitude only. Typical...
 
Indu 8 months ago
 
which has only magnitude
 
raju 8 months ago
View all Questions »