Selling Price after a 90% Profit Margin is applied to an item that Cost $10

Given: Cost = $10,  Profit Margin = 90%
Profit Margin as a Decimal: 90% = 0.9
Formula:
Selling Price =  

Cost/ 1 – Profit Margin as a Decimal

Selling Price =  

$10/ 1 – 0.9

Selling Price =  

$10/ 0.1

Selling Price = $100
Notes:
Profit = Selling Price – Cost = $100 – $10 = $90
Markup Amount = Profit = $90
Markup Percentage =  

Markup Amount/ Cost

=  

$90/ $10

= 9 = 900%