EXPLANATION
Let's see the facts:
Bike Price: $99
Sold Price: $117
The percentage is given by the following relationship:
[tex]\text{Percentage: }\frac{\text{Selling price per unit}-Cost\text{ price per unit}}{Cost\text{ price per unit}}\cdot100[/tex]Replacing terms:
[tex]\text{Percentage =}\frac{117-99}{99}\cdot100[/tex][tex]\text{Percentage = 18.18\%}[/tex]Answer: The markup was 18.18%