French company marks 45% on the cost and we are supposed to find the equivalent markup on the selling price. The relation between the cost rate and the markup on the retail price can be combined as:
1/mr = 1/mc +1
where mr is the retail price; and
mc is the cost rate.
Retail price is same as the selling price so
1/mr = 1/0.45 + 1
1/mr = 3.222
so, mr = 1/3.222
therefore, equivalent markup on selling price = 0.310
