Let A be a 3 × 3 matrix having entries from the set - 1 , 0 , 1 . The number of all such matrices A having sum of all the entries equal to 5 , is _____

Step-by-step solution

Given Matrix 3 × 3 = − − − − − − − − − Here we can see we have to find nine elements whose sum is 5 Case 1 : When five 1's are there & four O's are there Now by division & distribution Method We get ⇒ 9 ! 5 ! 4 ! = 126           . . . i Case 2: when six 1's are there & one - 1 & two O's are there. Again by division & distribution Method we get ⇒ 9 ! 6 ! 2 ! 1 ! = 252           &#1