1. cost + 380%×cost = 4.80×cost = $1.88
... cost = $1.88/4.80 = $0.39
2. The relation between markup, cost, and selling price lets you find the cost, hence the markup.
... cost + markup = selling price
... cost + 0.75×cost = (1+0.75)×cost = 1.75×cost = $3.49
... cost = $3.49/1.75
... markup = 0.75×cost = 0.75×($3.49/1.75) = $3.49×(0.75/1.75) = $1.50
3. Same wording as 2. None of the given answers is correct.
... cost is $1.99; markup is 75%×$1.99 = $1.50; selling price = $1.99 + 1.50 = $3.49
(Have your teacher show you how to work this.)
5. Same as 2 and 3, but with different numbers.
... markup = (130%/230%)×(selling price) = (13/23)×$77.77 = $43.96
(Check: cost is 43.96/1.3 = 33.81; cost + markup = 33.81 + 43.96 = 77.77)
