If the sum of any of the columns of a matrix is 1 and that of any row is 1 then prove that there are equal number of rows and columns.
As stated in the problem,
(sum of all the elements of the matrix) = (Number of columns) * (sum of ...
A proof for sums of matrix columns is provided. The solution is detailed and well presented. The response received a rating of "5/5" from the student who originally posted the question.