A) The selling price of an Air Cooler is RO 120. The mark up is 55% on the selling price. The operating expenses are 35% of the cost. a) What is the mark up? b) What is the cost of the Air Cooler? c) Find the rate of mark up on cost. d) Find the operating expense. B) A retailer sells an article for RO 820 to the buyer and charges sales tax at a rate of 20%. If the retailer has to pay a value added tax of RO 12.600, find; a) The input tax b) The list price of the product the wholesaler sold to retailer c) The amount paid by the retailer to the wholesaler.