Easy percentages question but im stuck

Astore is having a sale in which all items are reduced by 20 percent. including tax, jennifer paid $21 for a pair of shorts. if the sales tax is 5 percent, what was the original price of the shorts

Ashley recently opened a store that sells only natural ingredients. she wants to advertise her products by distributing bags of samples in her neighborhood. it takes one person 22 minutes to prepare one bag. how many hours will it take to prepare 900900 bags of samples if ashley and 55 of her friends do the work?

Which container holds more, a half gallon milk jug or a 2 liter juice bottle