Question 1084360
let c be the cost.


he marks it up 20%.


let m be the marked up price.


m = c + .20 * c = 1.2 * c


he discounts it 10% off the marked up price.


let d be the discount price.


d = m - .10 * m = .9 * m


since m = 1.2 * c, replace m with 1.2 * c and you get the discounted price as:


d = .9 * (1.2 * c)


simplify to get d = 1.08 * 1.2 * c = 1.08 * c


he is selling at 8% above cost.


his profit margin is therefore 8%.


for example:


assume the cost is 100 dollars.


he marks it up 20% so the marked up price is 120 dollars.


he discount it 10% off the market up price, so he sells it at 90% of 120 dollars which is equal to 108 dollars.


his cost was 100 dollars.
his discount price was 108 dollars.
his profit is 8 dollars which is 8% more than his cost.