Suppose you are a computer salesman and your income depend on the total sales and comm issions earned for the computers that you sell. Commission rates vary depending on how many units you sold $($see chart below$).$ Your income equals to the total sales plus the commission where the commission equals to total sales times the commission rate. That is$,$ commission $=$ total sales $*$ commission rate and income $=$ total sales $+$ commission.

Total Sales

$\backslash$table$[[$Less than $200$ sold,Commission rate $\%],[$Greater or equal to $200$ sold,$8\%$