Assume P, Q, R and S are matrices of order 2 × m, k × n, m × 2 and 2 × 3 respectively. The restrictions on k, m and n, so that PQ + RS is defined are
Answer & explanation
Correct answer: option 4
| order (P) = 2 × m | order (R) = m × 2 |
| order (Q) = k × n | order (S) = 2 × 3 |
| for P × Q | for R × S |
| m = k | 2 = 2 |
| order (P × Q) = 2 × n | order (R × S) = m × 3 |
So for PQ+RS
order (PQ) = order (RS)
$2 × n=m × 3$
$n = 3, m = k = 2$