Let the matrix A = 1 2 3 0 1 2 0 0 1 and B A = A where B represent 3 × 3 order matrix. If the total number of 1 in matrix A - 1 and matrix B are p and q respectively, then the value of p + q is equal to

Step-by-step solution

A - 1 = 1 A a d j A ⇒ A - 1 = 1 - 2 1 0 1 - 2 0 0 1 A = 1 and B A = A B A A - 1 = A A - 1 ⇒ B = I Total number of 1 in matrix B = p = 3 and matrix A - 1 = q = 4 Hence, p + q = 7