Please help me understand step-by-step how to get to the answers provided by my professor:

1. Global Pet Foods sells bully sticks (dog treats) for $4.99 for the medium-sized and $6.99 for the large-sized. Their margin is 30% on the wholesale price. Likewise the wholesaler marks up the manufacturer's selling price by 20%. What is the manufacturer's selling price to the nearest cent for each product? ANSWER: $2.91, $4.08
2. Adrianna found beautiful leather purses on a recent trip to Italy that are made by a woman in her home. The Italian woman will sell each bag to Adrianna for $25, to which she will add on a margin of 50%. She knows that she cannot get the distribution she wants by selling them directly, so she intends to use a wholesaler that specializes in imported leather.Their usual margin is 25%.Retailers will add a 30% markup.What can a consumer expect to pay to the nearest cent for each Italian purse? ANSWER: $86.67
3. Lida Baday is a Toronto-based fashion designer, who also happens to be a Ryerson graduate. A consumer can expect to pay $500 for a Liday Baday dress.That price includes a 25% markup by the retailer and a 20% wholesale margin. To the nearest percent what is Lida Baday's selling price? ANSWER: $320
4. Bajar Greenhouse grows annuals under the President's Choice brand name to be sold in Loblaws stores.Consumers pay $6.99 for a six inch geranium. If Loblaws puts a 22% markup on its garden products, for what price to the nearest cent does Bajar's sell geraniums to Loblaws? ANSWER: $5.73
5. Loblaws also allows other garden centres to sell its President's Choice geraniums, which they in turn sell to consumers for $7.99.If the other garden centres add a 15% markup to the cost of the geraniums from Loblaws (see Q. 4), what is Loblaw's margin on these geraniums to the nearest percent? ANSWER: 18%
6. A screwdriver manufacturer buys raw materials for $1.85 per unit and sells its screwdrivers to a wholesaler for $3.75 per unit.The wholesaler then sells the screwdrivers to retailers for $5.35 per unit, and finally, consumers buy the screwdriver for $7.50 per unit.What is the percent margin per unit to the nearest whole number for the entire chain? ANSWER: 75%