A dealer offers a cash discount of 20% and still makes a profit of 20%. If he further sells 8 articles at a rate of 6 articles, then how much percentage above the cost price does he mark on each article?

$$\eqalign{ & \frac{{{\text{Cost price}}}}{{{\text{Marked price}}}} = \frac{{100 - {\text{Discount}}}}{{100 + {\text{Profit}}}} \cr & = \frac{{100 - 20}}{{100 + 20}} \cr & = \frac{{80}}{{120}} \cr} $$
\[\begin{array}{*{20}{c}} {{\text{Cost price}}}&{{\text{Marked price}}} \\ {\frac{{80}}{8} = 10}&{\frac{{120}}{6} = 20} \end{array}\]
Above = 20 - 10 = 10
Above % = $$\frac{{10}}{{10}}$$ × 100 = 100%