It costs charlie's car repair shop $27 to change the oil. the shop charges their costumers $40 for an oil change. what is the percent of markup in the cost of an oil change?

Cost Price for oil change =$27 
Charge for the customers =$40 
Markup cost = Difference between selling price and cost price =$40-$27=$13  
To find the percent of markup, divide the markup cost by the cost price and multiply it by 100. 
Markup percent = (13/27)*100 
 =48.15%