Answer:
The selling price is $30.80
Explanation:
Buying price = $28.00
Rick applies a mark up of 10%
The percentage of buying price is 100%
The percentage of selling price is 100% + 10% = 110%
So $28 = 100%
What about 110%?
Cross multiplying gives;
110/100 × $28 = $30.80
The selling price is $30.80