Given:
Matrix = 60 elements
To solve this, we need to
take into account that each row must contain the same number of elements. So, we
need to find which of the options do not divide evenly into 60 (the options are
30, 60, 10, and 18).
So we check each of the choices to see if 1 of them divides evenly with 60.
60 / 60 = 1 (divides evenly)
60 / 30 = 2 (divides
evenly)
60 / 10 = 6 (divides
evenly)
60 / 18 = 3.3.3333333333333333333333333333333 (does not divide evenly)
Therefore, 18 cannot equal the number of rows of the matrix.
