An online virus$-$scan service provider, Metlock, is expanding its offerings to include an optimizing service to users$-$ it can scan the consumer's hard drive for duplicate files, suggest more efficient ways to save or archive photos and movies, and much more. The problem is that the company's own cost information has been lost$-$not due to a virus but due to human error. Charlee, the office manager, is trying to recreate some of the information to use in pricing Metlock's newest optimizing service. Here is what she was able to dig up:

Known Information for Virus$-$ScanService

Selling price

Gross margin $\%$

$$28$ per scan

$50\%$

Costs of Optimizing Service

Labor cost

MOH cost $($includes software, utilities, etc.$)$

$$6$ per scan

$$24$ per scan

$($a$)$

For Metlock's virus$-$scan service, calculate the current cost$-$plus markup percentage $($based on service cost rather than full cost, since the selling and administrative expense information has been lost$).($Round answer to O decimal places, e$.$g$.15\%.)$

Markup percentage on service cost

$\%$