**Author details**

Wilfred Isak April<sup>1</sup> \*, Daniel Ileni Itenge2 , David Namalenga3 and Petrus Stepfanus Erwee4

\*Address all correspondence to: drwilfredisakapril@gmail.com

1 University of Namibia, Windhoek, Namibia

2 Ministry of Labour, Otjiwarongo, Namibia

3 Dinapama Manufacturing and Supplies, Windhoek, Namibia

4 Namibian Mathematics Institute, Omeya, Namibia
