If the gross profit rate on the sale of a radio is 28% of the selling price, what is the gross profit rate based on the cost of the radio?

Answer 1

say we sold for 100 dollars
we made 28 dollars
and it cost 100 -28= 72 dollars
so
we made 28 dollars on an item costing us 72 dollars
28/72 = .388 = 38.8 %