The Question of the week.

To determine the markup (on the cost), we have

(New Price - Old Price) / Old Price

(1.00 - .80) /  .80  =

.20 / .80  =   2/8   = 1/4   =  25%

(this is a proportion)

80/100 = x/100

now cross multiply

100x = 8000

divide by 100 on both sides

x = 80

x = 80%

and there's your answer!

i appoligize ahead oh time if you arent supposed to do this in a proportion... that is just what i instantly thought :)

actually it might be 20% because 80% sounds too high

ah that makes more sense