Q28 / 75 · NTA Abhyas (JEE Main) 2020 · Mathematics · Matrices

Let A=aij3×3 and B=bij3×3, where bij=aij+aji2 ∀i,j. Number of such matrices A whose elements are selected from the set 0,1,2,3 such that A=B, are

  • A
    29
  • Correct answer
    B
    212
  • C
    26
  • D
    28

Solution

A=a11a12a13a21a22a23a31a32a33 and B=b11b12b13b21b22b23b31b32b33
∵A=B⇒aij=bij=aij+aji2
⇒aij=aji
⇒A is a symmetric matrix

Hence, the number of such matrix=4×4×4×4×4×4=46=212

Hence, the correct answer is option: 'B'.

More Matrices Questions