Use the original price and the markdown to find the retail price. Original price: $80; Markdown: 16%

Which one ? is the answer and how to find this answer

Your food costs are $5,500. your total food sales are $11,000. what percent of your food sales do the food costs represent?

Acollection of coins has value of 64 cents. there are two more nickels than dimes and three times as many pennies as dimes in this collection. how many of each kind of coin are in the collection?