Given: The selling price is $52.50 and the cost price is $31.11.
To find: Percent Markup based on selling price.
Explanation:
The percentage markup based on selling price will be:

Plug the value S.P.= 52.20 and C.P.=31.11 in the above formula to get:

Rounding it to the nearest tenth percent we get 41.0%
Final Answer: The percent markup is 41%.