In a matrix of order \(3 \times 4\), which of the following elements does not exist?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → \(a_{43}\)
In \(a_{ij}\) the first suffix i is the row number and the second suffix j is the column number.
A matrix of order \(3 \times 4\) has 3 rows and 4 columns, so
\(i = 1, 2, 3\) and \(j = 1, 2, 3, 4\)
The element \(a_{43}\) needs a fourth row, which the matrix does not have. The elements \(a_{34}\), \(a_{14}\) and \(a_{23}\) all lie within 3 rows and 4 columns.