Question

How many entries are there in a 3×3 matrix​

Answer 1

Answer:

198 is the correct answer

Answer 2

$\huge{\purple{Answer}}$

How many entries are there in a 3×3 matrix?

Hence, the total number of combinations

( i.e. total number of matrices with entries from {0, 1 and 2} for which the sum of diagonal entries of MTMis 5)

is 126+72 = 198.

Note: One should always remember the formulas of permutation and combinations. And also have the knowledge in the matrix.

Khadijah21