Transportation- CA final Costing

Introduce Dummy,if necessary, after converting a Maximisation problem into a Minimisation problem.

No.You cannoy do both ways. If you first do Balancing the matrix by introducing a dummy row or column having 0 value and then do conversion of a Maximisation matrix into a Minimisation matrix by subtracting all numbers from the highest number, you will also subtract the dummy 0s & as a result the matrix values will change at stage 2 itself leading to a wrong answer.