**Author details**

Motsa Sandile Sydney1\*, Samuel Felix Mutua1 and Shateyi Stanford2

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

1 School of Mathematics, Statistics & Computer Science, University of KwaZulu-Natal, Scottsville, Pietermaritzburg, South Africa

2 University of Venda, Thohoyandou, Limpopo Province, South Africa
