Answer: So, By 48% cost price is marked up.
Step-by-step explanation:
Since we have given that
Selling price of gaming cards = 9.99 per card
Cost price of gaming cards = 6.75 per card
Percentage that mark up the cost price by
![(9.99-6.75)/(6.75)* 100\\\\(3.24)/(6.75)* 100\\\\=(324)/(6.75)\\\\=48\%](https://img.qammunity.org/2019/formulas/mathematics/middle-school/ixn46z5wtmosfyrpj298n26sbwvjhc5dhn.png)
So, By 48% cost price is marked up.