Given:
Anna sells certain pair of hearings $45.20 per pair.
Overhead expenses $6 per pair.
35% operating profit on selling price.
[tex]\text{Amount markup per pair =(45.20}\times\frac{35}{100})+6[/tex][tex]\text{Amount markup per pair =}15.82+6[/tex][tex]\text{Amount markup per pair = \$21.82}[/tex]Therefore, the amount of markup is $21.82.