part 1. With a 25% mark up on selling price and a cost of $270, what is the selling price?

part 2. If the mark up on a product is 80% of selling price, what is the equivalent markup on cost?

part 3. With a product cost of $6, what should the selling price be to produce a 20% markup on selling price?

part 4. If a product now selling for $1000 was first marked up by the seller 50% on cost, what did the product originally cost the seller?